Which codec is supported on the Cisco PVDM2 DSP modules but not on the PVDM3 DSP modules?
A.
G.728
It will enable early media cut-through.
B.
G.729B
It will generate local ring back.
C.
G.729AB
It will do nothing because the message is informational.
D.
G.723
It will terminate the call because this is an unsupported message format.
E.
G.726
It will take the FXS port offhook.
G.
723 codec support or the G.729 codec can be as an alternative on the PVDM3
http://www.cisco.com/c/en/us/td/docs/routers/access/1900/software/configuration/guide/Softwar
e_Configuration/pvdm3HYPERLINK
“http://www.cisco.com/c/en/us/td/docs/routers/access/1900/software/configuration/guide/Softwa
re_Configuration/pvdm3_config.html”_HYPERLINK
“http://www.cisco.com/c/en/us/td/docs/routers/access/1900/software/configuration/guide/Softwa
re_Configuration/pvdm3_config.html”config.html
QUESTION 154
Refer to the exhibit.
Which option describes how this Cisco IOS SIP gateway, with an analog phone attached to its FXS
port, handles an incoming informational SIP 180 response message without SDP?
A.
G.728
It will enable early media cut-through.
B.
G.729B
It will generate local ring back.
C.
G.729AB
It will do nothing because the message is informational.
D.
G.723
It will terminate the call because this is an unsupported message format.
E.
G.726
It will take the FXS port offhook.
Explanation:
All codecs that are supported on the PVDM2 are supported on the PVDM3, except that the PVDM3
does not support the G.723 (G.723.1 and G.723.1A) codecs. The PVDM2 can be used to provideThe Session Initiation Protocol (SIP) feature allows you to specify whether 180 messages with
Session Description Protocol (SDP) are handled in the same way as 183 responses with SDP. The 180
Ringing message is a provisional or informational response used to indicate that the INVITE message
has been received by the user agent and that alerting is taking place. The 183 Session Progress
response indicates that information about the call state is present in the message body media
information. Both 180 and 183 messages may contain SDP, which allows an early media session to
be established prior to the call being answered.
Prior to this feature, Cisco gateways handled a 180 Ringing response with SDP in the same manner
as a 183 Session Progress response; that is, the SDP was assumed to be an indication that the far end
would send early media. Cisco gateways handled a 180 response without SDP by providing local
ringback, rather than early media cut-through. This feature provides the capability to ignore the
presence or absence of SDP in 180 messages, and as a result, treat all 180 messages in a uniformmanner. The SIP—Enhanced 180 Provisional Response Handling feature allows you to specify which
call treatment, early media or local ringback, is provided for 180 responses with SDP.http://www.cisco.com/c/en/us/td/docs/ios/voice/cube/configuration/guide/vb_book/vb_book/vb_
1506.html