Enabling Early Media Negotiation - HP FlexNetwork MSR Series Configuration Manual

Configuration procedure
To configure periodic refresh of SIP sessions:
Step
1. Enter system view.
2. Enter voice view.
3. Enter SIP client view.
4. Enable periodic refresh of
SIP sessions and set the
maximum and minimum
session expiration time.

Enabling early media negotiation

With early media negotiation enabled, if the device is the called party, it sends a 183 session
progress response with media information to the calling party to perform early media negotiation and
automatically plays tones to the calling party. The called party can play only common ring back tones
to the calling party. However, in some actual applications, such as the caller ring back tone (CRBT)
service, servers are required to play the ring back tones to the calling party. Therefore, you need to
disable early media negotiation on the called party for those applications. After that, the called party
sends a 180 ringing response without media information to the calling party, and the calling party
receives only CRBTs played by the server instead of the common ring back tones played by the
called party.
To enable early media negotiation:
Step
1. Enter system view.
2. Enter voice view.
3. Enter SIP client view.
4. Enable early media
negotiation on the device.
Configuring VRF-aware SIP
Before you perform this task, you must have completed L3VPN configurations.
Command
system-view
voice-setup
sip
timer session-expires seconds
[ minimum min-seconds ]
Command
system-view
voice-setup
sip
early-media enable
159
Remarks
N/A
N/A
N/A
Optional.
By default,.
•
The periodic refresh of SIP
sessions is not enabled
automatically. That is, if
periodic refresh of SIP
sessions is disabled on the
called party but enabled on
the calling party, the called
party will enable periodic
refresh of SIP sessions after
negotiation.
•
The minimum session
duration is 90 seconds.
Remarks
N/A
N/A
N/A
Optional.
Enabled by default. In other
words, when the device is the
called party, it sends a 183
session progress response with
media information to the called
party.