diff --git a/src/main/kotlin/de/gmuth/ipp/client/CupsClient.kt b/src/main/kotlin/de/gmuth/ipp/client/CupsClient.kt
index 68f0245c..d8f39710 100644
--- a/src/main/kotlin/de/gmuth/ipp/client/CupsClient.kt
+++ b/src/main/kotlin/de/gmuth/ipp/client/CupsClient.kt
@@ -6,7 +6,6 @@ package de.gmuth.ipp.client
 
 import de.gmuth.ipp.client.IppExchangeException.ClientErrorNotFoundException
 import de.gmuth.ipp.client.WhichJobs.All
-import de.gmuth.ipp.core.IppAttributesGroup
 import de.gmuth.ipp.core.IppOperation
 import de.gmuth.ipp.core.IppOperation.*
 import de.gmuth.ipp.core.IppRequest
@@ -22,7 +21,7 @@ import java.util.logging.Logger.getLogger
 // https://www.cups.org/doc/spec-ipp.html
 class CupsClient(
     val cupsUri: URI = URI.create("ipp://localhost"),
-    val ippClient: IppClient = IppClient()
+    private val ippClient: IppClient = IppClient()
 ) {
     constructor(host: String = "localhost") : this(URI.create("ipp://$host"))
 
@@ -31,6 +30,10 @@ class CupsClient(
     var userName: String? by config::userName
     var cupsClientWorkDirectory = File("CUPS/${cupsUri.host}")
 
+    private val cupsServer =
+        IppPrinter(cupsUri, ippClient = ippClient, getPrinterAttributesOnInit = false)
+            .apply { workDirectory = cupsClientWorkDirectory }
+
     init {
         if (cupsUri.scheme == "ipps") config.trustAnyCertificateAndSSLHostname()
     }
@@ -160,55 +163,53 @@ class CupsClient(
     // Delegate to IppClient
     //----------------------
 
+    fun basicAuth(user: String, password: String) =
+        ippClient.basicAuth(user, password)
+
     internal fun ippRequest(operation: IppOperation, printerURI: URI = cupsUri) =
         ippClient.ippRequest(operation, printerURI)
 
     internal fun exchange(ippRequest: IppRequest) =
         ippClient.exchange(ippRequest)
 
-    fun basicAuth(user: String, password: String) =
-        ippClient.basicAuth(user, password)
-
-    //-----------------------
-    // Delegate to IppPrinter
-    //-----------------------
-
-    protected val ippPrinter: IppPrinter by lazy {
-        IppPrinter(cupsUri, ippClient = ippClient, getPrinterAttributesOnInit = false)
-            .apply { workDirectory = cupsClientWorkDirectory }
-    }
+    //---------
+    // Get Jobs
+    //---------
 
     fun getJobs(
         whichJobs: WhichJobs? = null,
         limit: Int? = null,
-        requestedAttributes: List<String>? = ippPrinter.getJobsRequestedAttributes
+        requestedAttributes: List<String>? = cupsServer.getJobsRequestedAttributes
     ) =
-        ippPrinter.getJobs(whichJobs = whichJobs, limit = limit, requestedAttributes = requestedAttributes)
+        cupsServer.getJobs(whichJobs = whichJobs, limit = limit, requestedAttributes = requestedAttributes)
+
+    fun getJob(id: Int) =
+        cupsServer.getJob(id)
 
-    //----------------------------
-    // Create printer subscription
-    //----------------------------
+    //--------------------
+    // Create Subscription
+    //--------------------
 
-    fun createPrinterSubscription(
+    fun createSubscription(
         // https://datatracker.ietf.org/doc/html/rfc3995#section-5.3.3.4.2
         notifyEvents: List<String>? = listOf("all"),
         notifyLeaseDuration: Duration? = null,
         notifyTimeInterval: Duration? = null
     ) =
-        ippPrinter.createPrinterSubscription(notifyEvents, notifyLeaseDuration, notifyTimeInterval)
+        cupsServer.createPrinterSubscription(notifyEvents, notifyLeaseDuration, notifyTimeInterval)
 
-    fun createPrinterSubscription(
+    fun createSubscription(
         vararg notifyEvents: String = arrayOf("all"),
         notifyLeaseDuration: Duration? = null,
         notifyTimeInterval: Duration? = null
     ) =
-        createPrinterSubscription(notifyEvents.toList(), notifyLeaseDuration, notifyTimeInterval)
+        createSubscription(notifyEvents.toList(), notifyLeaseDuration, notifyTimeInterval)
 
     //-----------------------------
-    // Setup IPP Everywhere Printer
+    // Create IPP Everywhere Printer
     //-----------------------------
 
-    fun setupIppEverywherePrinter(
+    fun createIppEverywherePrinter(
         printerName: String,
         deviceUri: URI,
         printerInfo: String? = null,
@@ -218,7 +219,7 @@ class CupsClient(
         deviceUri,
         printerInfo,
         printerLocation,
-        ppdName = "everywhere"
+        ppdName = "airprint"
     ).apply {
         updateAttributes("printer-name")
         log.info(toString())
@@ -238,9 +239,6 @@ class CupsClient(
         updateAttributes()
     }
 
-    private val IppRequest.printerGroup: IppAttributesGroup
-        get() = getSingleAttributesGroup(Printer)
-
     // ---------------------------
     // Get jobs and save documents
     // ---------------------------
@@ -278,7 +276,7 @@ class CupsClient(
             .apply {
                 log.info { "Found ${jobOwners.size} job ${if (jobOwners.size == 1) "owner" else "owners"}: $jobOwners" }
                 log.info { "Found $size jobs (which=$whichJobs) where $numberOfJobsWithoutDocuments jobs have no documents" }
-                log.info { "Saved $numberOfSavedDocuments documents of ${size.minus(numberOfJobsWithoutDocuments.toInt())} jobs with documents to directory: ${ippPrinter.workDirectory}" }
+                log.info { "Saved $numberOfSavedDocuments documents of ${size.minus(numberOfJobsWithoutDocuments.toInt())} jobs with documents to directory: ${cupsServer.workDirectory}" }
             }
     }
 
@@ -294,7 +292,7 @@ class CupsClient(
         pollEvery: Duration = Duration.ofSeconds(1),
         commandToHandleFile: String? = null // e.g. "open" -> open <filename> with Preview on MacOS
     ) {
-        createPrinterSubscription(whichJobEvents, notifyLeaseDuration = leaseDuration)
+        createSubscription(whichJobEvents, notifyLeaseDuration = leaseDuration)
             .pollAndHandleNotifications(pollEvery, autoRenewSubscription = autoRenewLease) { event ->
                 log.info { event.toString() }
                 with(event.getJob()) {
@@ -343,5 +341,4 @@ class CupsClient(
         }
         return documents.map { it.file!! }
     }
-
 }
\ No newline at end of file
diff --git a/src/main/kotlin/de/gmuth/ipp/client/IppClient.kt b/src/main/kotlin/de/gmuth/ipp/client/IppClient.kt
index 348d45c6..749fbbfb 100644
--- a/src/main/kotlin/de/gmuth/ipp/client/IppClient.kt
+++ b/src/main/kotlin/de/gmuth/ipp/client/IppClient.kt
@@ -25,7 +25,7 @@ import javax.net.ssl.HttpsURLConnection
 
 typealias IppResponseInterceptor = (request: IppRequest, response: IppResponse) -> Unit
 
-open class IppClient(val config: IppConfig = IppConfig()) {
+open class IppClient(val config: IppConfig = IppConfig()) : IppExchange {
     protected val log = getLogger(javaClass.name)
 
     var responseInterceptor: IppResponseInterceptor? = null
@@ -47,18 +47,16 @@ open class IppClient(val config: IppConfig = IppConfig()) {
     // Build IppRequest
     //-----------------
 
-    protected val requestCounter = AtomicInteger(1)
+    private val requestCounter = AtomicInteger(1)
 
     fun ippRequest(
         operation: IppOperation,
-        printerUri: URI,
-        jobId: Int? = null,
+        printerUri: URI? = null,
         requestedAttributes: Collection<String>? = null,
         userName: String? = config.userName
     ) = IppRequest(
         operation,
         printerUri,
-        jobId,
         requestedAttributes,
         userName,
         config.ippVersion,
@@ -71,8 +69,8 @@ open class IppClient(val config: IppConfig = IppConfig()) {
     // Exchange IppRequest for IppResponse
     //------------------------------------
 
-    fun exchange(request: IppRequest): IppResponse {
-        val ippUri: URI = request.printerUri
+    override fun exchange(request: IppRequest): IppResponse {
+        val ippUri: URI = request.printerOrJobUri
         log.finer { "send '${request.operation}' request to $ippUri" }
         val response = httpPost(toHttpUri(ippUri), request)
         log.fine { "$ippUri: $request => $response" }
@@ -151,11 +149,11 @@ open class IppClient(val config: IppConfig = IppConfig()) {
     ) =
         when {
             responseCode == 401 -> with(request) {
-                "User \"$requestingUserName\" is not authorized for operation $operation on $printerUri"
+                "User \"$requestingUserName\" is not authorized for operation $operation on $printerOrJobUri"
             }
 
             responseCode == 426 -> {
-                "HTTP status $responseCode, $responseMessage, Try ipps://${request.printerUri.host}"
+                "HTTP status $responseCode, $responseMessage, Try ipps://${request.printerOrJobUri.host}"
             }
 
             responseCode != 200 -> {
diff --git a/src/main/kotlin/de/gmuth/ipp/client/IppDocument.kt b/src/main/kotlin/de/gmuth/ipp/client/IppDocument.kt
index 9edf4eff..8aec0e98 100644
--- a/src/main/kotlin/de/gmuth/ipp/client/IppDocument.kt
+++ b/src/main/kotlin/de/gmuth/ipp/client/IppDocument.kt
@@ -9,15 +9,16 @@ import de.gmuth.ipp.core.IppString
 import java.io.File
 import java.io.IOException
 import java.io.InputStream
-import java.util.logging.Logger
+import java.io.OutputStream
 import java.util.logging.Logger.getLogger
 import kotlin.io.path.createTempDirectory
 
 class IppDocument(
-    val job: IppJob,
-    val attributes: IppAttributesGroup,
-    val inputStream: InputStream
-) {
+    private val job: IppJob,
+    documentAttributes: IppAttributesGroup,
+    private val inputStream: InputStream
+) : IppObject(job, documentAttributes) {
+
     private val log = getLogger(javaClass.name)
 
     val number: Int
@@ -31,9 +32,8 @@ class IppDocument(
 
     var file: File? = null
 
-    fun readBytes() = inputStream.readBytes().also {
-        log.fine { "read ${it.size} bytes of $this" }
-    }
+    fun readBytes() = inputStream.readBytes()
+        .also { log.fine { "Read ${it.size} bytes of $this" } }
 
     fun filenameSuffix() = when (format) {
         "application/octet-stream" -> "bin"
@@ -46,7 +46,7 @@ class IppDocument(
 
     fun filename() = StringBuilder().run {
         var suffix: String? = filenameSuffix()
-        with(job) {
+        job.run {
             append("job-$id")
             if (numberOfDocuments > 1) append("-doc-$number")
             job.getOriginatingUserNameOrAppleJobOwnerOrNull()?.let { append("-$it") }
@@ -62,13 +62,16 @@ class IppDocument(
         toString().replace('/', '_')
     }
 
+    fun copyTo(outputStream: OutputStream) =
+        inputStream.copyTo(outputStream)
+
     fun save(
         directory: File = createTempDirectory().toFile(),
         file: File = File(directory, filename()),
         overwrite: Boolean = true
     ) = file.also {
         if (file.isFile && !overwrite) throw IOException("File '$file' already exists")
-        inputStream.copyTo(file.outputStream())
+        copyTo(file.outputStream())
         this.file = file
         log.info { "Saved $this" }
     }
@@ -76,14 +79,12 @@ class IppDocument(
     fun runCommand(commandToHandleFile: String) =
         Runtime.getRuntime().exec(arrayOf(commandToHandleFile, file!!.absolutePath))
 
-    override fun toString() = StringBuilder().run {
-        append("document #$number ($format) of job #${job.id}")
+    override fun objectName() = "Document #$number"
+
+    override fun toString() = StringBuilder(objectName()).run {
+        append(" ($format) of job #${job.id}")
         if (attributes.containsKey("document-name")) append(" '$name'")
         if (file != null) append(": $file (${file!!.length()} bytes)")
         toString()
     }
-
-    fun log(logger: Logger) =
-        attributes.log(logger, title = "DOCUMENT-$number")
-
 }
\ No newline at end of file
diff --git a/src/main/kotlin/de/gmuth/ipp/client/IppEventNotification.kt b/src/main/kotlin/de/gmuth/ipp/client/IppEventNotification.kt
index e4724175..b30af589 100644
--- a/src/main/kotlin/de/gmuth/ipp/client/IppEventNotification.kt
+++ b/src/main/kotlin/de/gmuth/ipp/client/IppEventNotification.kt
@@ -8,12 +8,12 @@ import de.gmuth.ipp.attributes.JobState
 import de.gmuth.ipp.attributes.PrinterState
 import de.gmuth.ipp.core.IppAttributesGroup
 import de.gmuth.ipp.core.IppString
-import java.util.logging.Logger
 
 class IppEventNotification(
-    val subscription: IppSubscription,
-    val attributes: IppAttributesGroup
-) {
+    private val subscription: IppSubscription,
+    eventNotificationAttributes: IppAttributesGroup
+) : IppObject(subscription, eventNotificationAttributes) {
+
     val sequenceNumber: Int
         get() = attributes.getValue("notify-sequence-number")
 
@@ -50,12 +50,10 @@ class IppEventNotification(
     val printerIsAcceptingJobs: Boolean
         get() = attributes.getValue("printer-is-accepting-jobs")
 
-    // get job from printer
+    // Get job from printer
     fun getJob() = subscription.printer.getJob(jobId)
 
-    // -------
-    // Logging
-    // -------
+    override fun objectName() = "Event notification #$sequenceNumber $subscribedEvent"
 
     @SuppressWarnings("kotlin:S3776")
     override fun toString() = StringBuilder().run {
@@ -71,8 +69,4 @@ class IppEventNotification(
         }
         toString()
     }
-
-    fun log(logger: Logger) =
-        attributes.log(logger, title = "event notification #$sequenceNumber $subscribedEvent")
-
 }
\ No newline at end of file
diff --git a/src/main/kotlin/de/gmuth/ipp/client/IppExchange.kt b/src/main/kotlin/de/gmuth/ipp/client/IppExchange.kt
new file mode 100644
index 00000000..8af08fcb
--- /dev/null
+++ b/src/main/kotlin/de/gmuth/ipp/client/IppExchange.kt
@@ -0,0 +1,14 @@
+package de.gmuth.ipp.client
+
+import de.gmuth.ipp.core.IppRequest
+import de.gmuth.ipp.core.IppResponse
+
+/**
+ * Copyright (c) 2020-2023 Gerhard Muth
+ */
+
+fun interface IppExchange {
+
+    fun exchange(request: IppRequest): IppResponse
+
+}
\ No newline at end of file
diff --git a/src/main/kotlin/de/gmuth/ipp/client/IppInspector.kt b/src/main/kotlin/de/gmuth/ipp/client/IppInspector.kt
new file mode 100644
index 00000000..28319a95
--- /dev/null
+++ b/src/main/kotlin/de/gmuth/ipp/client/IppInspector.kt
@@ -0,0 +1,138 @@
+package de.gmuth.ipp.client
+
+/**
+ * Copyright (c) 2023 Gerhard Muth
+ */
+
+import de.gmuth.ipp.attributes.*
+import de.gmuth.ipp.attributes.TemplateAttributes.jobName
+import de.gmuth.ipp.core.IppOperation.*
+import java.io.File
+import java.net.URI
+import java.util.logging.Logger.getLogger
+
+object IppInspector {
+    private val log = getLogger(javaClass.name)
+    var directory: String = "inspected-printers"
+
+    const val pdfA4 = "blank_A4.pdf"
+
+    fun inspect(printerUri: URI, cancelJob: Boolean = true) =
+        IppPrinter(printerUri).inspect(cancelJob)
+
+    /**
+     * Exchange a few IPP requests and save the IPP responses returned by the printer.
+     * Operations:
+     * - Get-Printer-Attributes
+     * - Print-Job, Get-Jobs, Get-Job-Attributes
+     * - Hold-Job, Release-Job, Cancel-Job
+     */
+    private fun IppPrinter.inspect(cancelJob: Boolean) {
+        log.info { "Inspect printer $printerUri" }
+
+        val printerModel = with(StringBuilder()) {
+            if (isCups()) append("CUPS-")
+            append(makeAndModel.text.replace("\\s+".toRegex(), "_"))
+            toString()
+        }
+        log.info { "Printer model: $printerModel" }
+
+        ippClient.saveMessages = true
+        ippClient.saveMessagesDirectory = File(directory, printerModel).apply {
+            if (!isDirectory && !mkdirs()) throw RuntimeException("Failed to create directory: $path")
+        }
+        workDirectory = ippClient.saveMessagesDirectory
+
+        attributes.run {
+            // Media
+            if (containsKey("media-supported")) log.info { "Media supported: $mediaSupported" }
+            if (containsKey("media-ready")) log.info { "Media ready: $mediaReady" }
+            if (containsKey("media-default")) log.info { "Media default: $mediaDefault" }
+            // URIs
+            log.info { "Communication channels supported:" }
+            communicationChannelsSupported.forEach { log.info { "  $it" } }
+        }
+
+        val pdfResource = when {
+            !attributes.containsKey("media-ready") -> {
+                log.warning { "media-ready not supported" }
+                pdfA4
+            }
+
+            mediaReady.contains("iso-a4") || mediaReady.contains("iso_a4_210x297mm") -> pdfA4
+            mediaReady.contains("na_letter") || mediaReady.contains("na_letter_8.5x11in") -> "blank_USLetter.pdf"
+            else -> {
+                log.warning { "No PDF available for media '$mediaReady', trying A4" }
+                pdfA4
+            }
+        }
+
+        ippConfig.userName = "ipp-inspector"
+        runInspectionWorkflow(pdfResource, cancelJob)
+    }
+
+    private fun IppPrinter.runInspectionWorkflow(pdfResource: String, cancelJob: Boolean) {
+
+        log.info { "> Get printer attributes" }
+        getPrinterAttributes()
+
+        if (supportsOperations(CupsGetPPD)) {
+            log.info { "> CUPS Get PPD" }
+            savePPD(file = File(workDirectory, "0-${name.text}.ppd"))
+        }
+
+        if (supportsOperations(IdentifyPrinter)) {
+            val action = with(identifyActionsSupported) { if (contains("sound")) "sound" else first() }
+            log.info { "> Identify by $action" }
+            identify(action)
+        }
+
+        log.info { "> Validate job" }
+        val response = try {
+            validateJob(
+                jobName("Validation"),
+                DocumentFormat.OCTET_STREAM,
+                Sides.TwoSidedShortEdge,
+                PrintQuality.Normal,
+                ColorMode.Color,
+                Media.ISO_A3
+            )
+        } catch (ippExchangeException: IppExchangeException) {
+            ippExchangeException.response
+        }
+        log.info { response.toString() }
+
+        log.info { "> Print job $pdfResource" }
+        printJob(
+            IppInspector::class.java.getResourceAsStream("/$pdfResource"),
+            jobName(pdfResource),
+
+            ).run {
+            log.info { toString() }
+
+            log.info { "> Get jobs" }
+            for (job in getJobs()) {
+                log.info { "$job" }
+            }
+
+            if (supportsOperations(HoldJob, ReleaseJob)) {
+                log.info { "> Hold job" }
+                hold()
+                log.info { "> Release job" }
+                release()
+            }
+
+            if (cancelJob) {
+                log.info { "> Cancel job" }
+                cancel()
+            }
+
+            log.info { "> Update job attributes" }
+            updateAttributes()
+
+            ippClient.saveMessages = false
+            log.info { "> Wait for termination" }
+            waitForTermination()
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/main/kotlin/de/gmuth/ipp/client/IppJob.kt b/src/main/kotlin/de/gmuth/ipp/client/IppJob.kt
index cdec6523..5dda5b6d 100644
--- a/src/main/kotlin/de/gmuth/ipp/client/IppJob.kt
+++ b/src/main/kotlin/de/gmuth/ipp/client/IppJob.kt
@@ -15,16 +15,14 @@ import java.io.InputStream
 import java.net.URI
 import java.time.Duration
 import java.time.ZonedDateTime
-import java.util.logging.Level
-import java.util.logging.Level.INFO
-import java.util.logging.Logger
 import java.util.logging.Logger.getLogger
 
+@SuppressWarnings("kotlin:S1192")
 class IppJob(
     val printer: IppPrinter,
-    var attributes: IppAttributesGroup,
+    jobAttributes: IppAttributesGroup,
     subscriptionAttributes: IppAttributesGroup? = null
-) {
+) : IppObject(printer, jobAttributes) {
 
     companion object {
         var defaultDelay: Duration = Duration.ofSeconds(1)
@@ -33,7 +31,6 @@ class IppJob(
 
     private val log = getLogger(javaClass.name)
     var subscription: IppSubscription? = subscriptionAttributes?.let { IppSubscription(printer, it) }
-    val ippConfig = printer.ippConfig
 
     //--------------
     // IppAttributes
@@ -52,15 +49,12 @@ class IppJob(
         get() = JobState.fromAttributes(attributes)
 
     val stateReasons: List<String>
-        @SuppressWarnings("kotlin:S1192")
         get() = attributes.getValues("job-state-reasons")
 
     val name: IppString
-        @SuppressWarnings("kotlin:S1192")
         get() = attributes.getValue("job-name")
 
     val originatingUserName: IppString
-        @SuppressWarnings("kotlin:S1192")
         get() = attributes.getValue("job-originating-user-name")
 
     val originatingHostName: IppString
@@ -93,7 +87,6 @@ class IppJob(
         get() = attributes.getTimeValue("time-at-completed")
 
     val appleJobOwner: String // only supported by Apple CUPS
-        @SuppressWarnings("kotlin:S1192")
         get() = attributes.getTextValue("com.apple.print.JobInfo.PMJobOwner")
 
     fun isPending(updateStateAttributes: Boolean = false) = stateIs(updateStateAttributes, Pending)
@@ -105,7 +98,7 @@ class IppJob(
     fun isTerminated(updateStateAttributes: Boolean = false) = stateIs(updateStateAttributes, Canceled)
             || stateIs(false, Aborted) || stateIs(false, Completed)
 
-    protected fun stateIs(updateStateAttributes: Boolean, expectedState: JobState): Boolean {
+    private fun stateIs(updateStateAttributes: Boolean, expectedState: JobState): Boolean {
         if (updateStateAttributes) updateAttributes("job-state", "job-state-reasons")
         return state == expectedState
     }
@@ -210,7 +203,7 @@ class IppJob(
         val request = documentRequest(SendDocument, lastDocument, documentName, documentNaturalLanguage).apply {
             documentInputStream = inputStream
         }
-        attributes = exchange(request).jobGroup
+        attributes.put(exchange(request).jobGroup)
     }
 
     @JvmOverloads
@@ -235,10 +228,10 @@ class IppJob(
         val request = documentRequest(SendURI, lastDocument, documentName, documentNaturalLanguage).apply {
             operationGroup.attribute("document-uri", Uri, documentUri)
         }
-        attributes = exchange(request).jobGroup
+        attributes.put(exchange(request).jobGroup)
     }
 
-    protected fun documentRequest(
+    private fun documentRequest(
         operation: IppOperation,
         lastDocument: Boolean,
         documentName: String?,
@@ -251,20 +244,35 @@ class IppJob(
         }
     }
 
+    //--------------
+    // CUPS-Move-Job
+    //--------------
+
+    fun cupsMoveJob(printerUri: URI) = exchange(
+        ippRequest(CupsMoveJob).apply {
+            require(uri.host == printerUri.host) { "Printer $printerUri must be on the same server: ${uri.host}" }
+            createAttributesGroup(Job).attribute("job-printer-uri", Uri, printerUri)
+        }
+    )
+
+    fun cupsMoveJob(ippPrinter: IppPrinter) =
+        cupsMoveJob(ippPrinter.printerUri)
+
     //------------------------
     // Create-Job-Subscription
     //------------------------
 
+    @JvmOverloads
     fun createJobSubscription(notifyEvents: List<String>? = null): IppSubscription {
         val request = ippRequest(CreateJobSubscriptions).apply {
             printer.checkNotifyEvents(notifyEvents)
             createSubscriptionAttributesGroup(notifyEvents, notifyJobId = id)
         }
-        val subscriptionAttributes = exchange(request).getSingleAttributesGroup(Subscription)
+        val subscriptionAttributes = exchange(request).subscriptionGroup
         return IppSubscription(printer, subscriptionAttributes).apply {
             subscription = this
             if (notifyEvents != null && !events.containsAll(notifyEvents)) {
-                log.warning { "server ignored some notifyEvents $notifyEvents, subscribed events: $events" }
+                log.warning { "Server ignored some notifyEvents $notifyEvents, subscribed events: $events" }
             }
         }
     }
@@ -291,7 +299,7 @@ class IppJob(
 
     @JvmOverloads
     fun cupsGetDocument(documentNumber: Int = 1): IppDocument {
-        log.fine { "cupsGetDocument #$documentNumber for job #$id" }
+        log.fine { "CupsGetDocument #$documentNumber for job #$id" }
         val response = exchange(ippRequest(CupsGetDocument).apply {
             operationGroup.attribute("document-number", Integer, documentNumber)
         })
@@ -319,28 +327,26 @@ class IppJob(
     fun printerDirectory() =
         printer.printerDirectory(printerUri.toString().substringAfterLast("/"))
 
-    fun ippRequest(operation: IppOperation, requestedAttributes: List<String>? = null) =
+    private fun ippRequest(operation: IppOperation, requestedAttributes: List<String>? = null) =
         printer.ippRequest(
-            operation, id, requestedAttributes,
+            operation, requestedAttributes, printerUri = null,
             userName = when {
                 useJobOwnerAsUserName && attributes.containsKey("job-originating-user-name") -> originatingUserName.text
                 useJobOwnerAsUserName && attributes.containsKey("com.apple.print.JobInfo.PMJobOwner") -> appleJobOwner
-                else -> ippConfig.userName
+                else -> printer.ippConfig.userName
             }
-        )
-
-    fun exchange(request: IppRequest) =
-        printer.exchange(request)
+        ).apply { operationGroup.attribute("job-uri", Uri, uri) }
 
     // -------
     // Logging
     // -------
 
+    override fun objectName() = "Job #$id"
+
     @SuppressWarnings("kotlin:S3776")
-    override fun toString(): String = with(attributes) {
-        StringBuffer().run {
-            append("Job #$id:")
-            if (containsKey("job-state")) append(" state=$state")
+    override fun toString(): String = attributes.run {
+        StringBuilder(objectName()).run {
+            if (containsKey("job-state")) append(", state=$state")
             if (containsKey("job-state-reasons")) append(" (reasons=${stateReasons.joinToString(",")})")
             if (containsKey("job-name")) append(", name=$name")
             if (containsKey("job-impressions-completed")) append(", impressions-completed=$impressionsCompleted")
@@ -349,11 +355,8 @@ class IppJob(
             if (containsKey("com.apple.print.JobInfo.PMJobOwner")) append(", appleJobOwner=$appleJobOwner")
             if (containsKey("number-of-documents") || containsKey("document-count")) append(", number-of-documents=$numberOfDocuments")
             if (containsKey("job-printer-uri")) append(", printer-uri=$printerUri")
+            if (containsKey("job-uri")) append(", uri=$uri")
             toString()
         }
     }
-
-    @JvmOverloads
-    fun log(logger: Logger, level: Level = INFO) =
-        attributes.log(logger, level, title = "JOB-$id")
 }
\ No newline at end of file
diff --git a/src/main/kotlin/de/gmuth/ipp/client/IppObject.kt b/src/main/kotlin/de/gmuth/ipp/client/IppObject.kt
new file mode 100644
index 00000000..63d02cfe
--- /dev/null
+++ b/src/main/kotlin/de/gmuth/ipp/client/IppObject.kt
@@ -0,0 +1,26 @@
+package de.gmuth.ipp.client
+
+/**
+ * Copyright (c) 2023 Gerhard Muth
+ */
+
+import de.gmuth.ipp.core.IppAttributesGroup
+import de.gmuth.ipp.core.IppRequest
+import java.util.logging.Level
+import java.util.logging.Logger
+
+abstract class IppObject(
+    private val exchangeDelegate: IppExchange,
+    internal val attributes: IppAttributesGroup
+) : IppExchange {
+
+    override fun exchange(request: IppRequest) =
+        exchangeDelegate.exchange(request)
+
+    protected abstract fun objectName(): String
+
+    @JvmOverloads
+    fun log(logger: Logger, level: Level = Level.INFO) =
+        attributes.log(logger, level, title = objectName())
+
+}
\ No newline at end of file
diff --git a/src/main/kotlin/de/gmuth/ipp/client/IppPrinter.kt b/src/main/kotlin/de/gmuth/ipp/client/IppPrinter.kt
index 66519107..5679554f 100644
--- a/src/main/kotlin/de/gmuth/ipp/client/IppPrinter.kt
+++ b/src/main/kotlin/de/gmuth/ipp/client/IppPrinter.kt
@@ -8,7 +8,6 @@ import de.gmuth.ipp.attributes.*
 import de.gmuth.ipp.attributes.CommunicationChannel.Companion.getCommunicationChannelsSupported
 import de.gmuth.ipp.attributes.Marker.Companion.getMarkers
 import de.gmuth.ipp.attributes.PrinterState.*
-import de.gmuth.ipp.attributes.TemplateAttributes.jobName
 import de.gmuth.ipp.core.*
 import de.gmuth.ipp.core.IppOperation.*
 import de.gmuth.ipp.core.IppStatus.ClientErrorNotFound
@@ -18,21 +17,20 @@ import de.gmuth.ipp.iana.IppRegistrationsSection2
 import java.io.*
 import java.net.URI
 import java.time.Duration
-import java.util.logging.Level
 import java.util.logging.Level.*
-import java.util.logging.Logger
 import java.util.logging.Logger.getLogger
 import kotlin.io.path.createTempDirectory
 
 @SuppressWarnings("kotlin:S1192")
-open class IppPrinter(
+class IppPrinter(
     val printerUri: URI,
-    val attributes: IppAttributesGroup = IppAttributesGroup(Printer),
+    printerAttributes: IppAttributesGroup = IppAttributesGroup(Printer),
     ippConfig: IppConfig = IppConfig(),
-    val ippClient: IppClient = IppClient(ippConfig),
+    internal val ippClient: IppClient = IppClient(ippConfig),
     getPrinterAttributesOnInit: Boolean = true,
     requestedAttributesOnInit: List<String>? = null
-) {
+) : IppObject(ippClient, printerAttributes) {
+
     private val log = getLogger(javaClass.name)
     var workDirectory: File = createTempDirectory().toFile()
 
@@ -69,7 +67,7 @@ open class IppPrinter(
             try {
                 updateAttributes(requestedAttributesOnInit)
                 if (isStopped()) {
-                    log.info { toString() }
+                    log.fine { toString() }
                     alert?.let { log.info { "alert: $it" } }
                     alertDescription?.let { log.info { "alert-description: $it" } }
                 }
@@ -102,6 +100,9 @@ open class IppPrinter(
     val ippConfig: IppConfig
         get() = ippClient.config
 
+    fun basicAuth(user: String, password: String) =
+        ippClient.basicAuth(user, password)
+
     var getJobsRequestedAttributes = mutableListOf(
         "job-id", "job-uri", "job-printer-uri", "job-state", "job-name",
         "job-state-reasons", "job-originating-user-name"
@@ -237,15 +238,28 @@ open class IppPrinter(
     // Printer administration
     //-----------------------
 
-    fun pause() = exchangeIppRequest(PausePrinter)
-    fun resume() = exchangeIppRequest(ResumePrinter)
-    fun purgeJobs() = exchangeIppRequest(PurgeJobs)
-    fun enable() = exchangeIppRequest(EnablePrinter)
-    fun disable() = exchangeIppRequest(DisablePrinter)
-    fun holdNewJobs() = exchangeIppRequest(HoldNewJobs)
-    fun releaseHeldNewJobs() = exchangeIppRequest(ReleaseHeldNewJobs)
-    fun cancelJobs() = exchangeIppRequest(CancelJobs)
-    fun cancelMyJobs() = exchangeIppRequest(CancelMyJobs)
+    fun pause() = exchange(ippRequest(PausePrinter))
+    fun resume() = exchange(ippRequest(ResumePrinter))
+    fun purgeJobs() = exchange(ippRequest(PurgeJobs))
+    fun enable() = exchange(ippRequest(EnablePrinter))
+    fun disable() = exchange(ippRequest(DisablePrinter))
+    fun holdNewJobs() = exchange(ippRequest(HoldNewJobs))
+    fun releaseHeldNewJobs() = exchange(ippRequest(ReleaseHeldNewJobs))
+    fun cancelJobs() = exchange(ippRequest(CancelJobs))
+    fun cancelMyJobs() = exchange(ippRequest(CancelMyJobs))
+
+    fun cupsGetPPD(copyTo: OutputStream? = null) = exchange(ippRequest(CupsGetPPD))
+        .apply { copyTo?.let { documentInputStream!!.copyTo(it) } }
+
+    fun savePPD(
+        directory: File = workDirectory,
+        filename: String = "$name.ppd",
+        file: File = File(directory, filename)
+    ) =
+        file.also {
+            cupsGetPPD(it.outputStream())
+            log.info { "Saved PPD $it" }
+        }
 
     //------------------------------------------
     // Get-Printer-Attributes
@@ -358,7 +372,9 @@ open class IppPrinter(
     //-------------------------------
 
     fun getJob(jobId: Int) =
-        exchangeForIppJob(ippRequest(GetJobAttributes, jobId))
+        exchangeForIppJob(
+            ippRequest(GetJobAttributes).apply { operationGroup.attribute("job-id", Integer, jobId) }
+        )
 
     //---------------------------------
     // Get-Jobs (as Collection<IppJob>)
@@ -404,7 +420,7 @@ open class IppPrinter(
             checkNotifyEvents(notifyEvents)
             createSubscriptionAttributesGroup(notifyEvents, notifyLeaseDuration, notifyTimeInterval)
         }
-        val subscriptionAttributes = exchange(request).getSingleAttributesGroup(Subscription)
+        val subscriptionAttributes = exchange(request).subscriptionGroup
         return IppSubscription(this, subscriptionAttributes)
     }
 
@@ -419,9 +435,11 @@ open class IppPrinter(
 
     fun getSubscription(id: Int) = IppSubscription(
         this,
-        exchange(ippRequest(GetSubscriptionAttributes).apply {
-            operationGroup.attribute("notify-subscription-id", Integer, id)
-        }).getSingleAttributesGroup(Subscription)
+        exchange(
+            ippRequest(GetSubscriptionAttributes)
+                .apply { operationGroup.attribute("notify-subscription-id", Integer, id) }
+        )
+            .subscriptionGroup
     )
 
     //---------------------------------------------
@@ -450,32 +468,30 @@ open class IppPrinter(
     // delegate to IppClient
     //----------------------
 
-    fun ippRequest(
+    internal fun ippRequest(
         operation: IppOperation,
-        jobId: Int? = null,
         requestedAttributes: Collection<String>? = null,
-        userName: String? = ippConfig.userName
+        userName: String? = ippConfig.userName,
+        printerUri: URI? = this.printerUri
     ) = ippClient
-        .ippRequest(operation, printerUri, jobId, requestedAttributes, userName)
+        .ippRequest(operation, printerUri, requestedAttributes, userName)
 
-    fun exchange(request: IppRequest) = ippClient.exchange(request.apply {
+    override fun exchange(request: IppRequest) = super.exchange(request.apply {
         checkIfValueIsSupported("ipp-versions-supported", version!!)
         checkIfValueIsSupported("operations-supported", code!!.toInt())
         checkIfValueIsSupported("charset-supported", attributesCharset)
     })
 
-    protected fun exchangeIppRequest(operation: IppOperation) = exchange(ippRequest(operation))
-
-    protected fun exchangeForIppJob(request: IppRequest): IppJob {
+    private fun exchangeForIppJob(request: IppRequest): IppJob {
         val response = exchange(request)
         if (response.status != SuccessfulOk) log.warning { "Job response status: ${response.status}" }
         if (request.containsGroup(Subscription) && !response.containsGroup(Subscription)) {
             request.log(log, WARNING, prefix = "REQUEST: ")
-            val events: List<String> = request.getSingleAttributesGroup(Subscription).getValues("notify-events")
+            val events: List<String> = request.subscriptionGroup.getValues("notify-events")
             throw IppException("printer/server did not create subscription for events: ${events.joinToString(",")}")
         }
         val subscriptionsAttributes = response.run {
-            if (containsGroup(Subscription)) getSingleAttributesGroup(Subscription) else null
+            if (containsGroup(Subscription)) subscriptionGroup else null
         }
         return IppJob(this, response.jobGroup, subscriptionsAttributes)
     }
@@ -484,9 +500,11 @@ open class IppPrinter(
     // Logging
     // -------
 
-    override fun toString() = StringBuilder("IppPrinter:").run {
-        if (attributes.containsKey("printer-name")) append(" name=$name")
-        if (attributes.containsKey("printer-make-and-model")) append(", makeAndModel=$makeAndModel")
+    override fun objectName() = "Printer $name ($makeAndModel)"
+
+    override fun toString() = StringBuilder("Printer").run {
+        if (attributes.containsKey("printer-name")) append(" $name")
+        if (attributes.containsKey("printer-make-and-model")) append(" ($makeAndModel)")
         append(", state=$state, stateReasons=$stateReasons")
         stateMessage?.let { if (it.text.isNotEmpty()) append(", stateMessage=$stateMessage") }
         if (attributes.containsKey("printer-is-accepting-jobs")) append(", isAcceptingJobs=$isAcceptingJobs")
@@ -495,10 +513,6 @@ open class IppPrinter(
         toString()
     }
 
-    @JvmOverloads
-    fun log(logger: Logger, level: Level = INFO) =
-        attributes.log(logger, level, title = "PRINTER-$name ($makeAndModel), $state $stateReasons")
-
     // ------------------------------------------------------
     // attribute value checking based on printer capabilities
     // ------------------------------------------------------
@@ -575,120 +589,4 @@ open class IppPrinter(
             if (!mkdirs() && !isDirectory) throw IOException("Failed to create printer directory: $path")
         }
 
-    /**
-     * Exchange a few IPP requests and save the IPP responses returned by the printer.
-     * Operations:
-     * - Get-Printer-Attributes
-     * - Print-Job, Get-Jobs, Get-Job-Attributes
-     * - Hold-Job, Release-Job, Cancel-Job
-     */
-    @JvmOverloads
-    fun inspect(directory: String = "inspected-printers", cancelJob: Boolean = true) {
-
-        log.info { "Inspect printer $printerUri" }
-
-        val printerModel = with(StringBuilder()) {
-            if (isCups()) append("CUPS_")
-            append(makeAndModel.text.replace("\\s+".toRegex(), "_"))
-            toString()
-        }
-        log.info { "Printer model: $printerModel" }
-
-        ippClient.saveMessages = true
-        ippClient.saveMessagesDirectory = File(directory, printerModel).apply {
-            if (!isDirectory && !mkdirs()) throw RuntimeException("Failed to create directory: $path")
-        }
-
-        attributes.run {
-            // Media
-            if (containsKey("media-supported")) log.info { "Media supported: $mediaSupported" }
-            if (containsKey("media-ready")) log.info { "Media ready: $mediaReady" }
-            if (containsKey("media-default")) log.info { "Media default: $mediaDefault" }
-            // URIs
-            log.info { "Communication channels supported:" }
-            communicationChannelsSupported.forEach { log.info { "  $it" } }
-        }
-
-        val pdfResource = when {
-            !attributes.containsKey("media-ready") -> {
-                log.warning { "media-ready not supported" }
-                "blank_A4.pdf"
-            }
-
-            mediaReady.contains("iso-a4") || mediaReady.contains("iso_a4_210x297mm") -> "blank_A4.pdf"
-            mediaReady.contains("na_letter") || mediaReady.contains("na_letter_8.5x11in") -> "blank_USLetter.pdf"
-            else -> {
-                log.warning { "No PDF available for media '$mediaReady', trying A4" }
-                "blank_A4.pdf"
-            }
-        }
-
-        ippConfig.userName = "ipp-inspector"
-        runInspectionWorkflow(pdfResource, cancelJob)
-    }
-
-    protected fun runInspectionWorkflow(pdfResource: String, cancelJob: Boolean) {
-
-        log.info { "> Get printer attributes" }
-        getPrinterAttributes()
-
-        if (supportsOperations(IdentifyPrinter)) {
-            val action = with(identifyActionsSupported) { if (contains("sound")) "sound" else first() }
-            log.info { "> Identify by $action" }
-            identify(action)
-        }
-
-        log.info { "> Validate job" }
-        val response = try {
-            validateJob(
-                jobName("Validation"),
-                DocumentFormat.OCTET_STREAM,
-                Sides.TwoSidedShortEdge,
-                PrintQuality.Normal,
-                ColorMode.Color,
-                Media.ISO_A3
-            )
-        } catch (ippExchangeException: IppExchangeException) {
-            ippExchangeException.response
-        }
-        log.info { response.toString() }
-
-        log.info { "> Print job $pdfResource" }
-        printJob(
-            IppPrinter::class.java.getResourceAsStream("/$pdfResource"),
-            jobName(pdfResource),
-
-            ).run {
-            log.info { toString() }
-
-            log.info { "> Get jobs" }
-            for (job in getJobs()) {
-                log.info { "$job" }
-            }
-
-            if (supportsOperations(HoldJob, ReleaseJob)) {
-                log.info { "> Hold job" }
-                hold()
-                log.info { "> Release job" }
-                release()
-            }
-
-            if (cancelJob) {
-                log.info { "> Cancel job" }
-                cancel()
-            }
-
-            log.info { "> Update job attributes" }
-            updateAttributes()
-
-            ippClient.saveMessages = false
-            if (!isTerminated()) {
-                log.info { "> Wait for termination" }
-                waitForTermination()
-            }
-
-            if (isAborted()) log(log)
-        }
-    }
-
 }
\ No newline at end of file
diff --git a/src/main/kotlin/de/gmuth/ipp/client/IppSubscription.kt b/src/main/kotlin/de/gmuth/ipp/client/IppSubscription.kt
index 7af5c749..06d7c404 100644
--- a/src/main/kotlin/de/gmuth/ipp/client/IppSubscription.kt
+++ b/src/main/kotlin/de/gmuth/ipp/client/IppSubscription.kt
@@ -8,22 +8,20 @@ import de.gmuth.ipp.client.IppExchangeException.ClientErrorNotFoundException
 import de.gmuth.ipp.core.IppAttributesGroup
 import de.gmuth.ipp.core.IppOperation
 import de.gmuth.ipp.core.IppOperation.*
-import de.gmuth.ipp.core.IppRequest
 import de.gmuth.ipp.core.IppString
-import de.gmuth.ipp.core.IppTag.*
+import de.gmuth.ipp.core.IppTag.EventNotification
+import de.gmuth.ipp.core.IppTag.Integer
 import java.time.Duration
 import java.time.Duration.ofSeconds
 import java.time.LocalDateTime
 import java.time.LocalDateTime.now
-import java.util.logging.Level
-import java.util.logging.Level.INFO
-import java.util.logging.Logger
 import java.util.logging.Logger.getLogger
 
 class IppSubscription(
     val printer: IppPrinter,
-    var attributes: IppAttributesGroup
-) {
+    subscriptionAttributes: IppAttributesGroup
+) : IppObject(printer, subscriptionAttributes) {
+
     private val log = getLogger(javaClass.name)
 
     private var lastSequenceNumber: Int = 0
@@ -54,8 +52,6 @@ class IppSubscription(
     val timeInterval: Duration
         get() = ofSeconds(attributes.getValue<Int>("notify-time-interval").toLong())
 
-    fun hasJobId() = attributes.containsKey("notify-job-id")
-
     //----------------------------
     // Get-Subscription-Attributes
     //----------------------------
@@ -64,10 +60,10 @@ class IppSubscription(
 
     @JvmOverloads
     fun getSubscriptionAttributes(requestedAttributes: List<String>? = null) =
-        exchange(ippRequest(GetSubscriptionAttributes, requestedAttributes = requestedAttributes))
+        exchange(ippRequest(GetSubscriptionAttributes, requestedAttributes = requestedAttributes)).subscriptionGroup
 
     fun updateAttributes() {
-        attributes.put(getSubscriptionAttributes().getSingleAttributesGroup(Subscription))
+        attributes.put(getSubscriptionAttributes())
     }
 
     //------------------
@@ -91,7 +87,8 @@ class IppSubscription(
     // Cancel-Subscription
     //--------------------
 
-    fun cancel() = exchange(ippRequest(CancelSubscription))
+    fun cancel() =
+        exchange(ippRequest(CancelSubscription))
 
     //-------------------
     // Renew-Subscription
@@ -107,18 +104,15 @@ class IppSubscription(
         }
 
     //-----------------------
-    // delegate to IppPrinter
+    // Delegate to IppPrinter
     //-----------------------
 
-    fun ippRequest(operation: IppOperation, requestedAttributes: List<String>? = null) =
-        printer.ippRequest(operation, requestedAttributes = requestedAttributes).apply {
-            operationGroup.attribute("notify-subscription-id", Integer, id)
-        }
-
-    fun exchange(request: IppRequest) = printer.exchange(request)
+    protected fun ippRequest(operation: IppOperation, requestedAttributes: List<String>? = null) =
+        printer.ippRequest(operation, requestedAttributes = requestedAttributes)
+            .apply { operationGroup.attribute("notify-subscription-id", Integer, id) }
 
     //------------------------------------
-    // poll and handle event notifications
+    // Poll and handle event notifications
     //------------------------------------
 
     var pollHandlesNotifications = false
@@ -136,12 +130,12 @@ class IppSubscription(
         fun expiresAfterDelay() = !leaseDuration.isZero && now().plus(pollEvery).isAfter(expiresAt.minusSeconds(2))
         try {
             pollHandlesNotifications = true
-            do {
+            while (pollHandlesNotifications) {
                 if (expired()) log.warning { "subscription #$id has expired" }
                 getNotifications().forEach { handleNotification(it) }
                 if (expiresAfterDelay() && autoRenewSubscription) renew(leaseDuration)
                 Thread.sleep(pollEvery.toMillis())
-            } while (pollHandlesNotifications)
+            }
         } catch (clientErrorNotFoundException: ClientErrorNotFoundException) {
             log.info { clientErrorNotFoundException.response!!.statusMessage.toString() }
         }
@@ -151,16 +145,13 @@ class IppSubscription(
     // Logging
     // -------
 
-    override fun toString() = StringBuilder("Subscription #$id:").run {
-        if (hasJobId()) append(" job #$jobId")
+    override fun objectName() = "Subscription #$id"
+
+    override fun toString() = StringBuilder(objectName()).run {
+        if (attributes.containsKey("notify-job-id")) append(", job #$jobId")
         if (attributes.containsKey("notify-events")) append(" events=${events.joinToString(",")}")
         if (attributes.containsKey("notify-time-interval")) append(" time-interval=$timeInterval")
         if (attributes.containsKey("notify-lease-duration")) append(" lease-duration=$leaseDuration (expires at $expiresAt)")
         toString()
     }
-
-    @JvmOverloads
-    fun log(logger: Logger, level: Level = INFO) =
-        attributes.log(logger, level, title = "subscription #$id")
-
 }
\ No newline at end of file
diff --git a/src/main/kotlin/de/gmuth/ipp/core/IppAttributesGroup.kt b/src/main/kotlin/de/gmuth/ipp/core/IppAttributesGroup.kt
index 09a654b7..e46e7112 100644
--- a/src/main/kotlin/de/gmuth/ipp/core/IppAttributesGroup.kt
+++ b/src/main/kotlin/de/gmuth/ipp/core/IppAttributesGroup.kt
@@ -6,6 +6,7 @@ package de.gmuth.ipp.core
 
 import java.io.BufferedWriter
 import java.io.File
+import java.net.URI
 import java.time.Instant
 import java.time.ZoneOffset
 import java.time.ZonedDateTime
@@ -51,6 +52,9 @@ class IppAttributesGroup(val tag: IppTag) : LinkedHashMap<String, IppAttribute<*
     fun <T> getValues(name: String) =
         get(name)?.values as T ?: throw IppException("Attribute '$name' not found in group $tag")
 
+    fun getUriValue(name: String) =
+        getValue<URI>(name)
+
     fun getTextValue(name: String) =
         getValue<IppString>(name).text
 
diff --git a/src/main/kotlin/de/gmuth/ipp/core/IppMessage.kt b/src/main/kotlin/de/gmuth/ipp/core/IppMessage.kt
index a29e61a4..1102159a 100644
--- a/src/main/kotlin/de/gmuth/ipp/core/IppMessage.kt
+++ b/src/main/kotlin/de/gmuth/ipp/core/IppMessage.kt
@@ -13,7 +13,7 @@ import java.util.logging.Logger.getLogger
 
 abstract class IppMessage() {
 
-    protected val log = getLogger(javaClass.name)
+    private val log = getLogger(javaClass.name)
     var code: Int? = null // unsigned short (16 bits)
     var requestId: Int? = null
     var version: String? = null
@@ -40,13 +40,19 @@ abstract class IppMessage() {
     val operationGroup: IppAttributesGroup
         get() = getSingleAttributesGroup(Operation)
 
+    val printerGroup: IppAttributesGroup // also used for CUPS-Printer-Operation requests
+        get() = getSingleAttributesGroup(Printer)
+
     val jobGroup: IppAttributesGroup
         get() = getSingleAttributesGroup(Job)
 
-    fun getAttributesGroups(tag: IppTag) =
+    val subscriptionGroup: IppAttributesGroup
+        get() = getSingleAttributesGroup(Subscription)
+
+    internal fun getAttributesGroups(tag: IppTag) =
         attributesGroups.filter { it.tag == tag }
 
-    fun getSingleAttributesGroup(tag: IppTag) = getAttributesGroups(tag).run {
+    internal fun getSingleAttributesGroup(tag: IppTag) = getAttributesGroups(tag).run {
         if (isEmpty()) throw IppException("No group found with tag '$tag' in $attributesGroups")
         single()
     }
@@ -168,6 +174,7 @@ abstract class IppMessage() {
         if (rawBytes == null) "" else " (${rawBytes!!.size} bytes)"
     )
 
+    @JvmOverloads
     fun log(logger: Logger, level: Level = INFO, prefix: String = "") {
         if (rawBytes != null) logger.log(level) { "${prefix}${rawBytes!!.size} raw ipp bytes" }
         logger.log(level) { "${prefix}version = $version" }
diff --git a/src/main/kotlin/de/gmuth/ipp/core/IppRequest.kt b/src/main/kotlin/de/gmuth/ipp/core/IppRequest.kt
index 9afcf864..729b7980 100644
--- a/src/main/kotlin/de/gmuth/ipp/core/IppRequest.kt
+++ b/src/main/kotlin/de/gmuth/ipp/core/IppRequest.kt
@@ -8,11 +8,23 @@ import de.gmuth.ipp.core.IppTag.*
 import java.net.URI
 import java.nio.charset.Charset
 import java.time.Duration
+import java.util.logging.Level
+import java.util.logging.Logger
 
 class IppRequest : IppMessage {
+    private val logger = Logger.getLogger(javaClass.name)
 
-    val printerUri: URI
-        get() = operationGroup.getValueOrNull("printer-uri") ?: throw IppException("Missing 'printer-uri'")
+    val printerOrJobUri: URI
+        @SuppressWarnings("kotlin:S1192")
+        get() = operationGroup.run {
+            when {
+                containsKey("printer-uri") -> getUriValue("printer-uri")
+                containsKey("job-uri") -> getUriValue("job-uri")
+                else -> throw IppException("Missing 'printer-uri' or 'job-uri' in IppRequest").also {
+                    log(logger, Level.WARNING)
+                }
+            }
+        }
 
     override val codeDescription: String
         get() = operation.toString()
@@ -31,7 +43,6 @@ class IppRequest : IppMessage {
     constructor(
         operation: IppOperation,
         printerUri: URI? = null,
-        jobId: Int? = null,
         requestedAttributes: Collection<String>? = null,
         requestingUserName: String? = null,
         version: String = "2.0",
@@ -41,7 +52,6 @@ class IppRequest : IppMessage {
     ) : super(version, requestId, charset, naturalLanguage) {
         code = operation.code
         operationGroup.run {
-            jobId?.let { attribute("job-id", Integer, it) }
             printerUri?.let { attribute("printer-uri", Uri, it) }
             requestedAttributes?.let { attribute("requested-attributes", Keyword, it) }
             requestingUserName?.let { attribute("requesting-user-name", NameWithoutLanguage, IppString(it)) }
diff --git a/src/main/kotlin/de/gmuth/ipp/core/IppResponse.kt b/src/main/kotlin/de/gmuth/ipp/core/IppResponse.kt
index b3ceb2c7..43b857fa 100644
--- a/src/main/kotlin/de/gmuth/ipp/core/IppResponse.kt
+++ b/src/main/kotlin/de/gmuth/ipp/core/IppResponse.kt
@@ -22,9 +22,6 @@ class IppResponse : IppMessage {
     val statusMessage: IppString
         get() = operationGroup.getValue("status-message")
 
-    val printerGroup: IppAttributesGroup
-        get() = getSingleAttributesGroup(Printer)
-
     val jobGroups: Collection<IppAttributesGroup>
         get() = getAttributesGroups(Job)
 
diff --git a/src/test/kotlin/de/gmuth/ipp/client/IppClientTests.kt b/src/test/kotlin/de/gmuth/ipp/client/IppClientTests.kt
index 85e671d3..40733cd8 100644
--- a/src/test/kotlin/de/gmuth/ipp/client/IppClientTests.kt
+++ b/src/test/kotlin/de/gmuth/ipp/client/IppClientTests.kt
@@ -15,8 +15,8 @@ class IppClientTests {
     @Test
     fun sendRequestToURIWithEncodedWhitespaces() {
         ippClient.ippRequest(GetPrinterAttributes, URI.create("ipp://0/PDF%20Printer")).run {
-            assertEquals("/PDF%20Printer", printerUri.rawPath)
-            assertEquals("/PDF Printer", printerUri.path)
+            assertEquals("/PDF%20Printer", printerOrJobUri.rawPath)
+            assertEquals("/PDF Printer", printerOrJobUri.path)
         }
     }
 }
diff --git a/src/test/kotlin/de/gmuth/ipp/client/IppExchangeExceptionTests.kt b/src/test/kotlin/de/gmuth/ipp/client/IppExchangeExceptionTests.kt
index d8c5eff5..96b9677c 100644
--- a/src/test/kotlin/de/gmuth/ipp/client/IppExchangeExceptionTests.kt
+++ b/src/test/kotlin/de/gmuth/ipp/client/IppExchangeExceptionTests.kt
@@ -16,10 +16,12 @@ class IppExchangeExceptionTests {
 
     @Test
     fun constructor() {
-        with(IppExchangeException(
+        with(
+            IppExchangeException(
                 IppRequest(IppOperation.GetPrinterAttributes).apply { encode() },
                 null, 400
-        )) {
+        )
+        ) {
             log(log)
             assertEquals(11, request.code)
             assertEquals(400, httpStatus)
diff --git a/src/test/kotlin/de/gmuth/ipp/client/IppJobTests.kt b/src/test/kotlin/de/gmuth/ipp/client/IppJobTests.kt
index e41102ee..22c55168 100644
--- a/src/test/kotlin/de/gmuth/ipp/client/IppJobTests.kt
+++ b/src/test/kotlin/de/gmuth/ipp/client/IppJobTests.kt
@@ -148,8 +148,9 @@ class IppJobTests {
                 remove("job-impressions-completed")
                 remove("number-of-documents")
                 remove("job-printer-uri")
+                remove("job-uri")
             }
-            assertEquals("Job #2366:", toString())
+            assertEquals("Job #2366", toString())
         }
     }
 
diff --git a/src/test/kotlin/de/gmuth/ipp/client/IppPrinterTests.kt b/src/test/kotlin/de/gmuth/ipp/client/IppPrinterTests.kt
index 0bf43e9a..7f9d7a1e 100644
--- a/src/test/kotlin/de/gmuth/ipp/client/IppPrinterTests.kt
+++ b/src/test/kotlin/de/gmuth/ipp/client/IppPrinterTests.kt
@@ -207,7 +207,7 @@ class IppPrinterTests {
 
     @Test
     fun pause() {
-        printer.ippClient.basicAuth("user", "password")
+        printer.basicAuth("user", "password")
         printer.pause()
     }
 
diff --git a/src/test/kotlin/de/gmuth/ipp/core/IppRequestTests.kt b/src/test/kotlin/de/gmuth/ipp/core/IppRequestTests.kt
index 8eed4ba7..da9350eb 100644
--- a/src/test/kotlin/de/gmuth/ipp/core/IppRequestTests.kt
+++ b/src/test/kotlin/de/gmuth/ipp/core/IppRequestTests.kt
@@ -26,7 +26,7 @@ class IppRequestTests {
             assertEquals(null, version)
             assertEquals(IppOperation.CreateJob, operation)
             createAttributesGroup(IppTag.Operation)
-            assertFailsWith<IppException> { printerUri }
+            assertFailsWith<IppException> { printerOrJobUri }
         }
     }
 
@@ -38,7 +38,7 @@ class IppRequestTests {
         assertEquals(IppOperation.StartupPrinter, request.operation)
         assertEquals(Charsets.UTF_8, request.attributesCharset)
         assertEquals("en", request.operationGroup.getValue("attributes-natural-language"))
-        assertEquals("ipp://foo", request.printerUri.toString())
+        assertEquals("ipp://foo", request.printerOrJobUri.toString())
         assertEquals("Startup-Printer", request.codeDescription)
         val requestEncoded = request.encode()
         assertEquals(97, requestEncoded.size)
@@ -48,7 +48,7 @@ class IppRequestTests {
     fun printJobRequest() {
         val request = IppRequest(
             IppOperation.PrintJob, URI.create("ipp://printer"),
-            0, listOf("one", "two"), "user"
+            listOf("one", "two"), "user"
         )
         request.documentInputStream = "pdl-content".byteInputStream()
         log.info { request.toString() }
@@ -65,7 +65,7 @@ class IppRequestTests {
             assertEquals(Charsets.UTF_8, getValue("attributes-charset"))
             assertEquals("en", getValue("attributes-natural-language"))
             assertEquals(URI.create("ipp://printer"), getValue("printer-uri"))
-            assertEquals(0, getValue("job-id"))
+            //assertEquals(0, getValue("job-id"))
             assertEquals(listOf("one", "two"), getValues("requested-attributes"))
             //assertEquals("user".toIppString(), getValue("requesting-user-name"))
         }