Cisco Cisco IOS Software Release 12.4(6)T

The SIP-to-SIP extended feature functionality for session border controller (SBC) enables the 
SIP-to-SIP functionality to conform with RFC 3261 to interoperate with SIP UAs. 

New SIP-to-SIP features available include:

Call Admission Control (based on CPU, memory, total calls)

Delayed Media Call

Media Inactivity

Modem passthrough 

TCP and UDP interworking 

Tcl scripts with SIP NOTIFY VoiceXML with SIP-to-SIP 

Transport Layer Security (TLS)

ENUM support

Lawful Intercept

Interoperability with Cisco Unified CallManager 5.0 and BroadSoft

Configuration information is included in the “

” chapter in the 

Release 12.4T, at the following URL:

Command reference information is included in the 

, Release 12.4T, 

at the following URL:

The following commands are new or modified for this feature: