Lucent Technologies 5ESS User Manual

IAM for this scenario has the COT indicator set, indicating that
an ISUP COT message will be received for the ISUP trunk.
1. The SIP INVITE includes:
• SDP offer with bearer session description for the OPS,
• encapsulated ISUP Initial Address Message,
• SIP Allow header indicating support for these methods:
INVITE, ACK, BYE, CANCEL, UPDATE, INFO,
OPTIONS,
• SIP Require header indicating that Precondition procedures
are required.
Due to the provisioning of the PSTN TO SIP MAPPING RULES
on RC/V 5.83, some call information is not populated in SIP
headers, even if the corresponding ISUP parameter is present in
the ISUP IAM:
• no carrier selection information in Request URI,
• no calling name information in the From header,
• no originating line information in the From header,
• no P-Asserted-Identity header, and
• no Diversion headers.
2. When the TPS has allocated bearer resources, it sends a 183
SESSION PROGRESS which includes:
• SDP answer with bearer session description for TPS,
• SIP Allow header indicating support for these methods:
INVITE, ACK, BYE, CANCEL, UPDATE, INFO,
OPTIONS,
• SIP Require header indicating that Precondition procedures
are required.
3. The OPS sends a SIP UPDATE message as part of the
preconditions procedures, after COT has been received from the
PSTN and 183 SESSION PROGRESS with SDP has been
received from the TPS. The UPDATE includes an SDP offer with
the same bearer IP address and port information as the SDP in
the original INVITE, but with different quality-of-service
attributes.
4. 200 OK UPDATE includes an SDP answer with the same bearer
IP address and port as the SDP in the 183 SESSION
PROGRESS, but with different quality-of-service attributes.
Message Flows
Call Flow
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Lucent Technologies 235-200-118
Issue 3.02B, March 2007

Lucent Technologies 5ESS Specifications

General

Brand	Lucent Technologies
Model	5ESS
Category	Switch
Language	English