R0106-HP MSR Router Series Voice Configuration Guide(V7)

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If the UAS fails to receive the PRACK message from the UAC within a specified time, the UAS
retransmits the 18x response.
4. The UAS returns a 200 OK.
For more information about reliable provisional responses, see RFC 3262.
You must enable reliable provisional responses and configure the same value for the value argument on
both the UAC and UAS.
The following describes the differences between rel1xx require and rel1xx supported:
• With the rel1xx require command configured, the UAC sends INVITE requests with the Require:
value header field to indicate its requirement for reliable provisional responses (18x responses with
the Require: value header field). If the rel1xx disable command is configured on the UAS, the UAS
returns a 420 response and disconnects the call.
• With the rel1xx supported command configured, the UAC sends INVITE requests with the Require:
value header field to indicate its support for reliable provisional responses. If the rel1xx disable
command is configured on the UAS, the UAS returns an unreliable provisional response (18x
response without the Supported: value header field). In this case, the call continues with unreliable
delivery of provisional responses.
To configure reliable provisional responses:
Ste
p
Command Remarks
1. Enter system view.
system-view N/A
2. Enter voice view.
voice-setup N/A
3. Enter SIP view.
sip N/A
4. Configure reliable provisional
responses.
rel1xx { disable | require value |
supported value }
By default, SIP messages carry the
Supported: value header field (the
rel1xx supported 100rel command
applies).
Configuring transport protocols for SIP calls
When you configure transport protocols, follows these restrictions and guidelines:
• Configure the same transport protocol on the called and calling devices. For example, if you
configure the session transport tcp command on the calling device, you must configure the
transport tcp command on the called device.
• To use TCP for calls, registrations, or subscriptions, enable the TCP listening port.
• You can configure the transport protocol both globally (in SIP view) and for a specific VoIP entity (in
VoIP entity view). The configuration in VoIP entity view takes precedence over the global
configuration. A VoIP entity uses the global configuration only when no transport protocol is
configured in VoIP entity view.