in section 4.3. Sending Non-REGISTER Requests of outbound rfc 5626:
If the UAC is using a Globally
Routable UA URI (GRUU) [RFC5627] that was instantiated using a
Contact header field value that included an "ob" parameter, the UAC
sends the request over the flow used for registration, and subsequent
requests will arrive over that same flow.
what does 'that was instantiated using a Contact header field value that
included an "ob" parameter' mean? which request the referred Contact
header belongs to?
-- juha