u may see new codecs in video technology in near future, as video is the most demanding area in the collaboration space. So, you can add more questions if you want. Does the product support G.711? Does the product support G.722? Does the product support G.723? Does the product support G.729 (G.729A, G.729B)? Does the product support G.722? Does the product support AMR-NB? Does the product support video codecs: H.261, H.263, H.264? Does the product support iLBC? Does the product support iSAC? Does the product support Media Codec Transcoding (G.711 to G.729, and SO on)? 170 SIP Trunking Does the product support Media Codec Negotiation? Does the product support Media Codec Prioritization? Does the product support Secure Real-Time Transport Protocol (SRTP) and SRTP to RTP conversion? Does the product support RTCP? Does the product support MIME type (RFC-3555)? SIP to H.323 Interworking Support SIP is a standard protocol introduced by the IETF in 1999 to carry VoIP. Because it was created by the IETF, it approaches voice and multimedia from the Internet or IP perspec- tive. H.323 emerged around 1996, and as an International Telecommunication Union stan- dard was designed from a telecommunications perspective. Both standards have the same objective-to enable voice and multimedia convergence with IP protocols. Although we are talking about SIP trunking, there are existing networks with the H.323 protocol. Both H.323 and SIP use RTP/RTCP and SRTP to transport the media. But if we look into the basic call signaling, call setup, message definition, message encoding, load sharing, load balancing, addressing, address resolution, capability negotiation, conferenc- ing, multicast signaling, authentication, encryption, and SO on, they are different. So, when you place an SBC to interwork between your SIP and H.323 network, you need to make sure the product support has a minimum of the following criteria: Full support for H.323 version 4 interworking to SIP H.323 Fast Start (FS)-SIP and vice versa H.323 Slow Start (SS)-SIP and v