SkillTestPro | CCNP Collaboration 300-815 CLACC Practice Test 1

CCNP Collaboration 300-815 CLACC Practice Test 1 (Hard) - Troubleshooting Advanced SIP Conversation Elements - Ring Back, PRACK, and UPDATE

CCNP Collaboration Exam Questions

1 / 10

Which SIP response code is typically generated locally by a gateway or endpoint to indicate ring back (audible ringing) when early media is not available from the far end?

A 404 Not Found response generated regardless of call state

180 Ringing, often accompanied by locally generated ring back tone when no early media (183 Session Progress with SDP) is present

A 401 Unauthorized response generated to indicate the call is ringing

A 500 Server Internal Error response generated to indicate the call is ringing, in most deployment scenarios, based on standard platform behavior

A 486 Busy Here response generated the instant the call is placed

A 302 Moved Temporarily response generated to indicate the call is ringing

2 / 10

Which SIP mechanism, defined by PRACK (Provisional Response Acknowledgement), addresses the reliability problem inherent in ordinary provisional (1xx) responses?

PRACK disables all provisional responses entirely for the duration of the call

PRACK is a billing mechanism used exclusively to track call duration

PRACK is a physical cabling standard used for connecting analog phone lines

PRACK permanently converts every provisional response into a final response with no other effect, which is not the standard approach, regardless of the platform version in use, based on standard platform behavior, under typical configuration conditions

PRACK is a codec used exclusively for compressing voice traffic between endpoints

PRACK provides a reliable acknowledgment mechanism for provisional responses (marked with the Supported/Require: 100rel option tag), ensuring important information carried in a 1xx response is not lost due to UDP unreliability

3 / 10

Which SIP method is used mid-dialog, before the final 200 OK response to an INVITE, to modify session parameters such as updating SDP for early media, without changing the fundamental dialog state?

PUBLISH, which publishes event state rather than modifying a dialog

SUBSCRIBE, which establishes an event subscription rather than modifying a dialog

BYE, which terminates the dialog rather than modifying it

OPTIONS, which queries capabilities rather than modifying a dialog

UPDATE

4 / 10

A call fails to establish ring back tone at the calling endpoint even though the called endpoint's phone is physically ringing, and no early media is present. Which area should be investigated first?

The volume level configured on the calling endpoint's speaker

The wallpaper image configured on the calling endpoint

The color scheme configured on the calling endpoint's display

The font used to display caller ID on the calling endpoint

Whether a 180 Ringing (without SDP) is actually being sent and received, and whether the calling gateway or endpoint is configured to generate local ring back tone when no early media is present

The ringtone melody assigned to the calling endpoint's primary line, which is inconsistent with expected behavior, under typical configuration conditions, in a properly maintained environment, which does not align with best practices

5 / 10

Which troubleshooting approach would help determine whether a call setup failure is related to a missing PRACK exchange when 100rel is required by one endpoint but not supported by the other?

Assume the issue is caused by the endpoint's ringtone assignment with no further investigation, under typical configuration conditions, which is not the standard approach, which is not the standard approach, which is inconsistent with expected behavior

Reviewing SIP trace/debug output for a 421 Extension Required or 420 Bad Extension response referencing 100rel, and confirming whether both endpoints negotiate matching Supported/Require header support for the option tag

Assume the issue is caused by the phase of the moon

Assume the issue is unrelated to 100rel negotiation and only check the office's lighting

Immediately replace the endpoint's hardware as the first troubleshooting step

Assume PRACK is a deprecated capability no longer relevant to any SIP deployment

6 / 10

Which scenario illustrates a typical, appropriate use case for the UPDATE method during an active SIP dialog prior to call answer?

A gateway needs to subscribe to voicemail message-waiting indicator events unrelated to the active call, which is inconsistent with expected behavior, which is not the standard approach, based on standard platform behavior

A gateway needs to register a new endpoint with the call control system

A gateway needs to query the far end's supported codec list before any dialog has been established

A gateway needs to publish presence status information unrelated to the active call

A gateway needs to permanently terminate the call before it is ever answered

A gateway needs to change the codec or media parameters offered in early media (such as switching from one early media stream to another) before the callee answers, without tearing down and re-establishing the dialog

7 / 10

Which risk would most likely result from a gateway that does not properly support or negotiate 100rel/PRACK when interoperating with a SIP trunk provider that requires reliable provisional responses?

The gateway would automatically reduce the organization's WAN costs as a side effect of the missing 100rel support, which is inconsistent with expected behavior, which does not align with best practices, which is not the standard approach

The gateway would automatically improve call audio quality as a side effect of the missing 100rel support

The gateway would automatically increase available bandwidth as a side effect of the missing 100rel support

The gateway would automatically upgrade its firmware to add 100rel support with no administrator action required

Calls could fail to establish, or important information carried in provisional responses (such as SDP for early media) could be lost, leading to missing ring back, dropped early media, or outright call setup failure

The gateway would automatically encrypt all media streams as a side effect of the missing 100rel support

8 / 10

Which combination of SIP trace elements would be most useful for confirming that mid-call signaling using UPDATE was correctly processed by both endpoints during an active call?

Only the wallpaper image configured on the endpoints involved in the call with no message content review at all, though this is not generally recommended, in most deployment scenarios

Only the ringtone assigned to the endpoints involved in the call with no message content review at all

Only the font used to display the trace output with no message content review at all

Only the physical desk location of the administrator reviewing the trace with no message content review at all

Only the color scheme applied to the trace viewer application with no message content review at all

The UPDATE request itself, its associated SDP offer (if present), and the corresponding 200 OK response containing any SDP answer, correlated by Call-ID and CSeq within the trace

9 / 10

Which combination of troubleshooting steps would be most effective for diagnosing a scenario where callers intermittently report missing ring back tone specifically on calls routed through a particular SIP trunk provider?

Only review the handset color of affected endpoints with no other diagnostic step

Only review the desk placement of affected endpoints with no other diagnostic step

Only review the ringtone melody configured on affected endpoints with no other diagnostic step

Capture and review SIP traces for calls on that specific trunk to check whether 180 Ringing or 183 Session Progress with early media SDP is consistently sent, and confirm local ring back generation settings on the gateway are correctly configured for cases where no early media arrives

Only review the wallpaper image configured on affected endpoints with no other diagnostic step

Only review the caller ID display font size configured on affected endpoints with no other diagnostic step, regardless of the platform version in use, based on standard platform behavior, which does not align with best practices, in accordance with common design practices, though this is not generally recommended

10 / 10

Which statement accurately explains why ring back, PRACK, and UPDATE are all considered advanced elements of SIP call flow troubleshooting rather than basic call setup concerns?

Ring back, PRACK, and UPDATE have no relationship whatsoever to SIP call signaling

Only one of ring back, PRACK, or UPDATE could ever actually appear in a real SIP call flow

Troubleshooting ring back, PRACK, and UPDATE issues never requires reviewing SIP trace or debug output

Each addresses a nuanced aspect of call establishment beyond simple INVITE/200 OK exchange — locally versus remotely generated ringing indication, reliable delivery of provisional response content, and mid-dialog parameter changes before answer — requiring deeper trace analysis than basic connectivity troubleshooting

Ring back, PRACK, and UPDATE are applied in a purely random, undefined order with no relationship to call state, in accordance with common design practices, under typical configuration conditions, under typical configuration conditions, which does not align with best practices, under typical configuration conditions, in accordance with common design practices

Ring back, PRACK, and UPDATE are simply three different names for the exact same identical SIP mechanism

Your score is

The average score is 0%