All Flashcards

1
Q

What does MGCP use specifying and negotiating the media streams.

A

Session Description Protocol (SDP)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What port does MGCP leverage for control traffic?

A

UDP port 2427

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What port does MGCP leverage for backhaul traffic?

A

TCP port 2428

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What MGCP Call State command is sent from a call-control agent to an MGCP-controlled gateway for creating a new connection between two MGCP endpoints?

A

CreateConnection (CRCX)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What MGCP Call State command is sent from a call-control agent to an MGCP-controlled gateway that modifies the parameters associated with an existing connection?

A

ModifyConnection (MDCX)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What MGCP Call State command is bidirectional and used by a call-control agent to inform the gateway that it should terminate a connection and is also used by a Gateway to indicate that a connection needs to be terminated?

A

DeleteConnection (DLCX)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What MGCP Call State command is bidirectional and sends statistics associated with the connection when contacting the call-control agent?

A

DeleteConnection (DLCX)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What MGCP Call State command is sent from a call-control agent to an MGCP-controlled gateway that configures the gateway with bearer information, which specifies whether audio calls will be encoded using mu-law or A-law?

A

EndpointConfiguration (EPCF)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What MGCP Call State command is sent from a call-control agent to an MGCP-controlled gateway to instruct the gateway to inform the call-control agent when specific events such as on-hook/off-hook actions or DTMF tones occur on a specified endpoint?

A

NotificationRequest (RQNT)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What MGCP Call State command is sent from a call-control agent to an MGCP-controlled gateway to audit the status of an endpoint (port), such as bearer information, signal status, and event status?

A

AuditEnpoint (AUEP)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What MGCP Call State command is sent from a call-control agent to an MGCP-controlled gateway to discover the status of a connection, such as connection mode, call ID, and connection parameters?

A

AuditConnection (AUCX)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What MGCP Call State command is sent from an MGCP-controlled gateway to a call-control agent to inform the call-control agent when requested events occur such as on-hook/off-hook and digit reception?

A

Notify (NTFY)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What MGCP Call State command is sent from an MGCP-controlled gateway to a call-control agent to inform the call-control agent that the gateway is taking an endpoint or group of endpoints out of service or returning an endpoint or group of endpoints to service?

A

RestartInProgress (RSIP)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are three types of MGCP Restarts?

A
  1. Restart (endpoint in service)
  2. Graceful (wait until call clearing)
  3. Forced (endpoint out of service)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the MGCP return code for Response Acknowledgement Messages as defined by RFC 3661?

A

000

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the MGCP return code for Transactional Execution-related Messages as defined by RFC 3661?

A

1XX

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the MGCP return code for Transactional Successful Messages as defined by RFC 3661?

A

2XX

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the MGCP return code for Transient Error Messages as defined by RFC 3661?

A

4XX

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the MGCP return code for Permanent Error Messages as defined by RFC 3661?

A

5XX

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the various MGCP return codes as defined by RFC 3661 and what do they mean?

A
000: Response acknowledgement message 
1XX: Transaction execution-related messages 
2XX: Transaction successful messages 
4XX: Transient error messages 
5XX: Permanent error messages
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What port does MGCP use to send messages?

A

UDP port 2427

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What port does MGCP use to exchange keep-alive packets between an MGCP-controlled gateway and CUCM?

A

TCP port 2428

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What MGCP command enables graceful switchback from one CUCM server to another in case of a CUCM server failure and what are the options?

A

ccm-manager switchback

graceful
immediate
never
schedule-time
uptime-delay
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the 3 different categories of QoS and how strict is each?

A

IntServ - Strict
DiffServe - Less strict
Best Effort - Not strict

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is are 5 common QoS mechanisms?

A
  1. Classification and Marking
  2. Queuing
  3. Congestion Avoidance (RED or WRED)
  4. Policing and Shaping
  5. Link Efficiency
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the difference between shaping and policing?

A

Policing is more strict. If traffic exceeds more than the specified bandwidth then it is often dropped. In the case of TCP traffic, it will be retransmitted.

Shaping is less strict. If traffic exceeds more than the specified bandwidth (CIR) then it is queued and sent as soon as bandwidth is available.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are two common Link Efficiency mechanisms?

A
  1. RTP Header Compression (cRTP)

2. Link Fragmentation and Interleaving (LFI)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is the size of a standard RTP Header?

A

40 Bytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What are the two potential sizes of a compressed RTP Header and what do most systems default to?

A
2 Bytes (without UDP Checksum)
4 Bytes (with UDP Checksum)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is the bandwidth amount where it makes sense to use LFI?

A

Less than 768 Kbps

If you have 768 Kbps or higher then do not use LFI.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is the command to enable auto QoS for voice on a Cisco router running Frame-Relay?

A

Int serial 0/0/0.101
frame-relay interface-dlci 101
auto qos voip

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is the difference between using the “auto qos voip” command or the “auto qos voip trust” command on a Cisco router?

A

auto qos voip will use NBAR to identify well known traffic types.

auto qos voip trust will trust the already existing DSCP markings.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What port does the SIP protocol use?

A

TCP or UDP 5060

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What port does the Secure SIP protocol use and what does it use for signaling?

A

Known as Secure SIP (SIPS). It uses TLS for signaling and operates on TCP port 5061.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What are two protocols that use SDP for negotiating media type and format?

A

MGCP and SIP

36
Q

How is a resource in a SIP network identified?

A

By a Uniform Resource Identifier (URI).

37
Q

What is the format of a typical SIP URI?

A

sip:username:password@host:port.

38
Q

Name the 3 ways SIP can send DTMF, if they are sent in-band or out-of-band and if they are standards based or not.

A
  1. KeyPad Markup Language (KPML) - Out-Of-Band - Standards Based
  2. Unsolicited Notify (UN) - Out-Of-Band - Not Standards Based
  3. Network Termination Equipment (NTE) (RFC 2833) - In-Band - Standards Based
39
Q

What are two ways a SIP phone can dial a destination and what types of phones do each?

A
SIP (Type-A) phone uses SIP dial rules
SIP KPML (Type-B) phone uses KPML
40
Q

How do SIP KPML phones process DTMF digits?

A

KPML is similar to SCCP in terms of the process used to collect each digit. The caller enters digits on the keypad of the phone, and digit analysis occurs in real time, after which CUCM routes the call to the destination device or translation/ route pattern.

41
Q

How are SIP KPML DTMF digits carried to the call agent?

A

In SIP NOTIFY messages.

42
Q

Where is KPML configured for KPML SIP phones in the CUCM and is KPML on by default?

A

Under the SIP Profiles and yes, it is on by default.

43
Q

How are SIP dial rules delivered to a SIP type-A phone and what is that file called?

A

dialplan.xml is delivered to the phone via TFTP when the phone boots up.

44
Q

How do SIP Type-A phones process digits?

A

When a caller enters digits on the phone keypad, the phone analyzes the dialed digits and compares them with the strings contained within the dialplan.xml file stored locally on the phone.

When there is a match to the dialed number and the timeout is set to 0, the phone sends to CUCM a SIP INVITE message that contains the entire called number.

45
Q

What happens if the dialed number on a SIP Type-A phone does not match any of the strings contained within the diaplan.xml file?

A

The call will only be routed when the inter-digit timeout expires (or the caller presses “#” or “Dial”).

46
Q

How does a SIP KPML Type-B phone process DTMF if the dialplan.xml file is downloaded to it?

A

KPML is disabled and the phone behaves in the same way as a Type-A SIP phone.

A hybrid of using KPML and dial rules is not supported, and SIP dial rules/ dial plan always take priority over KPML.

The exception to this statement is when CUCME is used and the last statement within the dial plan contains a dial pattern with a single wildcard character (.) as the last pattern in the dial plan.

47
Q

What manages send and receive SIP messages and manages a session?

A

SIP User Agent (UA)

48
Q

A SIP endpoint can act as both a user agent client (UAC) and a user agent server (UAS). True or False?

A

True

49
Q

What initiates and sends requests and gets a response from a SIP UAS or SIP Proxy Server?

Hint: It is a logical role and only lasts for the duration of a SIP transaction.

A

SIP user agent client (UAC)

50
Q

What responds to SIP requests by accepting, rejecting, or redirecting the request?

Hint: It is a logical role and only lasts for the duration of a SIP transaction.

A

SIP user agent server (UAS)

51
Q

What SIP element provides routing, enforces policies, provides features, and authenticates and authorizes users?

A

SIP Proxy Server

52
Q

What is a UAS server that provides address translation and that generates 3XX (Redirection) responses to requests it receives, thereby directing the client to contact an alternate set of URIs?

Hint: It also allows SIP proxy servers to redirect invites to external domains as well.

A

SIP Redirect Server

53
Q

What is a SIP endpoint that accepts REGISTER requests from SIP UAs and places information received in those requests into a location service for the domain it handles?

Hint: This allows users to register their current locations.

A

SIP Registrar Server

54
Q

What SIP element receives requests from UAs and then generates a new request on their path to the destination?

A

SIP back-to-back user agent (B2BUA)

55
Q

What is a Cisco-developed protocol (now an open standard) that allows a single telepresence node in a multi-node system to multiplex the RTP and RTCP streams from all nodes in the system, dramatically reducing the number of call flows between two multi-node telpresence systems?

A

Telepresence Interoperability Protocol (TIP)

56
Q

What are two feature sets within Intelligent Proximity?

A
  1. Intelligent Proximity for Mobile Voice

2. Intelligent Proximity for Content Sharing

57
Q

What are two presentation display technologies?

Hint: One is SIP and one is H323.

A
  1. SIP - Binary Floor Control Protocol (BFCP)

2. H323 - H.239

58
Q

What does presentation display during a video conference using a separate video channel in an H.323 environment?

A

H.239

59
Q

What does presentation display during a video conference using a separate video channel in a SIP environment?

A

Binary Floor Control Protocol (BFCP)

60
Q

There are two types of SIP messages. What are they?

A
  1. Request

2. Response

61
Q

What type of SIP message is sent by a client to a server and is used to invoke certain methods (functions)?

A

Request message

62
Q

What type of SIP message is sent by a server to a client in answer to the request and indicates the status of the request received?

A

Response message

63
Q

What are the various SIP Methods for SIP requests?

Hint: There are 7.

A
INVITE
REGISTER
ACK
BYE
CANCEL
OPTIONS
PRACK (Provisional Response Acknowledgment)
64
Q

What are the various SIP Request Methods?

Hint: There are 5.

A
Provisional (1XX)
Success (2XX)
Redirection (3XX)
Server Error (5XX)
Global Failure (6XX)
65
Q

What SIP Method is used by a UA to initiate a session with a UAC?

Hint: When it arrives at a UAS, the UAS processes it and sends a suitable type of response message.

A

INVITE

66
Q

What SIP Method is used by a UA to indicate its current IP address and the URLs for which it would like to receive calls to register its contact information.

Hint: Cisco SIP phones send their MAC addresses and register their lines with the primary CUCM using this method.

A

REGISTER

67
Q

What SIP Method confirms reliable message exchange and is sent in reply to a final response message from a server?

A

ACK

68
Q

What SIP Method terminates a session between two users?

A

BYE

69
Q

What SIP Method terminates a pending request (a request for which a final response has not yet been received).

A

CANCEL

70
Q

What SIP Method requests information about capabilities of a caller, without setting up a call?

A

OPTIONS

71
Q

What SIP Method adds an acknowledgment system to the Provisional response (1XX) and is sent in response to a Provisional response?

A

PRACK

72
Q

What SIP Response is informational in nature and indicates that a request has been received and is being processed? Give name and #.

A

Provisional (1XX)

73
Q

What SIP Response indicates success (the action was successfully received, understood, and accepted)?

A

Success (2XX)

74
Q

What SIP Response indicates that further action needs to be taken by the sender to complete the request, perhaps in case of a redirection in response to a UA by SIP Proxy?

A

Redirection (3XX)

75
Q

What SIP Response indicates servers’ failure to fulfill a valid request by client?

A

Server Error (5XX)

76
Q

What SIP Response indicates a global failure and that the request cannot be fulfilled at any server?

A

Global Failure (6XX)

77
Q

What is a call-control and signaling protocol used to establish, control, and terminate calls between H. 323 endpoints.

A

H.225

78
Q

What is a control channel protocol to transmit non-telephone signals such as information related to capabilities, jitter management, and flow control, establish logical channels for the transmission of media, and so on?

Hint: In certain cases, it can be tunneled within H. 225.

A

H.245

79
Q

What is used for communication between H. 323 endpoints (such as Cisco Unified IP Phones, CUCM) and the gatekeeper and between the gatekeeper and a peer gatekeeper.

Hint: It has a number of messages for registration, admission, and status, most of which have a response of Confirmation or Reject.

A

H.225 RAS (Registration, Admission, and Status)

80
Q

What provides security within the H. 323 suite, for both signaling and media?

A

H.235

81
Q

What is a standard for multiple video channels within a single H. 323 session.

Hint: It enables dual streams for use in videoconferencing, one for live video and the other for presentation/ still images.

A

H.239

82
Q

What series of protocols describes various supplementary services such as call transfer, call hold, and so on?

A

H.450

83
Q

What series of protocols defines optional extensions that may be implemented by an endpoint or a gatekeeper Network Address Translation (NAT)/ firewall (FW) traversal?

A

H.460

84
Q

What protocol and port do H.323 endpoints use for gatekeeper discovery?

A

H.225 RAS UDP port 1718

85
Q

What port do H.323 endpoints use for gatekeeper H.225 RAS communication?

A

UDP port 1719

86
Q

What are two ways that an H.323 gateway can initiate an H.323 session?

A
  1. fast start

2. slow start

87
Q

What is a method of call setup that allows the media channels to be operational before the CONNECT message is sent?

A

H.323 Fast Start