Configuring Call Handling
How to Configure Cisco Unified SIP SRST
166
Cisco Unified SCCP and SIP SRST System Administrator Guide
OL-13143-04
Configuring SIP-to-SIP Call Forwarding
SIP-to-SIP call forwarding (call routing) is available. Call forwarding is provided either by the phone or
by using a back-to-back user agent (B2BUA), which allows call forwarding on any dial peer. Calls into
a SIP device may be forwarded to other SIP or SCCP devices (including Cisco Unity, third-party
voice-mail systems, or an auto attendant or IVR system such as IPCC and IPCC Express). In addition,
SCCP IP phones may be forwarded to SIP phones.
Cisco Unity or other voice messaging systems connected by a SIP trunk or SIP user agent are able to
pass a message-waiting indicator (MWI) when a message is left. The SIP phone then displays the MWI
when indicated by the voice messaging system.
Note
SIP-to-H.323 call forwarding is not supported.
To configure SIP-to-SIP call forwarding, you must first allow connections between specific types of
endpoints in a Cisco IP-to-IP gateway. The
allow-connections
command grants this capability. Once the
SIP-to-SIP connections are allowed, you can configure call forwarding under an individual SIP phone
pool. Any of the following commands can be used to configure call forwarding, according to your needs:
•
Under
voice register pool
–
call-forward b2bua all
directory-number
–
call-forward b2bua busy
directory-number
–
call-forward b2bua mailbox
directory-number
–
call-forward b2bua noan
directory-number
[
timeout
seconds
]
Step 9
no vad
Example:
Router(config-register-pool)# no vad
Disables voice activity detection (VAD) on the VoIP dial
peer.
•
VAD is enabled by default. Because there is no comfort
noise during periods of silence, the call may seem to be
disconnected. You may prefer to set
no vad
on the SIP
phone pool.
Step 10
codec
codec-type
[
bytes
]
Example:
Router(config-register-pool)# codec g729r8
S
pecifies the codec supported by a single SIP phone or a
VoIP dial peer in a Cisco Unified SIP SRST environment.
The
codec
-
type
argument specifies the preferred codec and
can be one of the following:
•
g711alaw
: G.711 a–law 64,000 bps.
•
g711ulaw
: G.711 mu–law 64,000 bps.
•
g729r8
: G.729 8000 bps (default).
The
bytes
argument is optional and specifies the number of
bytes in the voice payload of each frame
Step 11
end
Example:
Router(config-register-pool)# end
Returns to privileged EXEC mode.
Command or Action
Purpose