> Is there any normative reference in relation of maximum > allowed length of Via branch parameter. One of our vendors > is sending a very long branch parameter and resultantly > the SIP message is being rejected with a 400 response. We > need to support this behavior with any normative references.
There is no maximum excluding potentially being restricted by maximum message size which is discussed within RFC 3261 section 18.1.1. RFC 3261 8.1.17 ABNF for via-branch and token indicate no maximum size. The following RFC 3261 8.1.17 snippet also indicates that the precise format of the branch (excluding magic cookie and need to be globally unique) is implementation-defined. "The branch ID inserted by an element compliant with this specification MUST always begin with the characters "z9hG4bK". These 7 characters are used as a magic cookie (7 is deemed sufficient to ensure that an older RFC 2543 implementation would not pick such a value), so that servers receiving the request can determine that the branch ID was constructed in the fashion described by this specification (that is, globally unique). Beyond this requirement, the precise format of the branch token is implementation-defined." _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
