Cisco Cisco Packet Data Interworking Function (PDIF) Documentation Roadmaps
Session Control Manager Overview
▀ How the SCM Works
▄ Cisco ASR 5000 Series Product Overview
OL-22938-01
Route Lists
Route lists are service level lists that assist in finding the next CSCF/UA hop. These are static routes and will override
any dynamic routes (based on DNS queries for FQDNs).
any dynamic routes (based on DNS queries for FQDNs).
Signaling Compression
The Session Initiation Protocol (SIP) is a text-based protocol designed for higher bandwidth networks. As such, it is
inherently less suited for lower bandwidth environments such as wireless networks. If a wireless handset uses SIP to set
up a call, the setup time is significantly increased due to the high overhead of text-based signaling messages.
inherently less suited for lower bandwidth environments such as wireless networks. If a wireless handset uses SIP to set
up a call, the setup time is significantly increased due to the high overhead of text-based signaling messages.
Signaling Compression (SigComp) is a solution for compressing/decompressing messages generated by application
protocols such as SIP. The P-CSCF component of the SCM uses SigComp to reduce call setup times on the access
network, typically between the P-CSCF and the UE. The following features are supported:
protocols such as SIP. The P-CSCF component of the SCM uses SigComp to reduce call setup times on the access
network, typically between the P-CSCF and the UE. The following features are supported:
SigComp Detection - P-CSCF detects if the UE supports SigComp and compresses messages it sends to the UE.
The P-CSCF also detects if messages it receives are compressed and decompresses them.
SigComp Parameter Configuration - P-CSCF allows the configuration of Decompression Memory Size
(DMS), State Memory Size (SMS), and Cycles Per Bit (CPB).
Failure Acknowledgement - P-CSCF replies with NACK on decompression failure.
SIP/SDP Static Dictionaries - P-CSCF supports the Session Initiation Protocol/Session Description Protocol
Static Dictionary for Signaling Compression.