Protocols: H.323 and SIP
Protocol and signal interworking

 H.323 to H.323 (including Cisco Unified CallManager)
  H.323 to SIP (including Cisco Unified CallManager)
  SIP to SIP (including Cisco Unified CallManager)
Media support: RTP and Real-Time Control Protocol (RTCP)
Media modes: Media flow-through, Media flow-around
Transport mode: TCP, UDP, TCP-to-UDP interworking
Fax support: T.38 Fax Relay, T.38 Digit Relay, Modem pass-through, Fax pass-through, Cisco Fax Relay
DTMF: H.245 Alphanumeric, H.245 Signal, RFC 2833, SIP Notify
CAC: RSVP, Maximum number of calls per trunk, CAC based on IP circuits
Security: IP Security (IPsec), SRTP, TLS
Voice media applications:
- Tool Command Language (TCL) scripts support for application customization
- Voice Extensible Markup Language (VoiceXML) script support for application customization
Lawful Intercept: Provide replicated packets to third-party mediation device
Session performance: 1000 concurrent calls with 2000 sessions in flow-through mode
Dimensions: 28.7 x 22.8 x 8.7 inches
Weight: 29.6 pounds