Voice over IP protocol families

There are currently four families of VoIP protocols: SIP, H.323 and H.248 based, and SIGTRAN.

Call Control

The call control protocols establish, modify and release connections.

SIP family

Based on IETF specifications:

H.323 family

Based on ITU-T specifications:

To correctly dissect these protocols preference settings of TCP, TPKT, Q.931 and H225 must be correctly set.

H.248 family

Based on IETF and ITU-T specifications:

SIGTRAN familiy

SIGTRAN is often used in connections towards PSTN.

Proprietary protocols

Cisco proprietary protocols:

Digium proprietary protocols:

Nortel proprietary protocols:


Both SIP and H323 uses the same RTP/RTCP transport protocols.

Movement toward secure communications involve these protocols

Authentication, Authorization and Accounting


As far as I know MGCP is a VoIP family too. So you should put MGCP + H248 in call control section.- Cedric MILLET

VOIPProtocolFamily (last edited 2008-08-12 09:03:27 by Pierrick CERISIER)