what are some differences between SIP and H.323 Solution * H.323 and SIP are used to run a VoIP service and multimedia communications. * H.323 is an older standard and is ISDN based. * H.323 is a binary protocol and is fairly complex in nature. * SIP was developed by the Internet Engineerin Task Force(IETF) and is text based(similar to HTTP). * Much of the infrastructure already in place to support HTTP has been adapted to support SIP. * IT managers within businesses are generally more comfortable with SIP because they are used to handlin HTTP traffic. * SIP is an open standard and solutions based on SIP are highly interoperable. * A lot of effort has gone into ensurin onteroperability and many manufactures work together to regularly test to ensure this. * Very few manufactures are workin on new H.323 implementations. .