> 1.can SUBSCRIBE/REFER create dialog?

Yes; see RFC 6665 and RFC 3515.

> 2.Is INVITE the only method creates a dialog?

No; see RFC 6665 and RFC 3515.

> 3.pseudo dialog corresponds only to REGISTER?

The term "pseudo dialog" is an informal description of how RFC 3261 section
10 indicates to reuse the same Call-ID with higher CSeq when refreshing the
binding.

As far as I know, no other request has been defined to reuse the same
Call-ID outside of dialog similar to REGISTER.

> 4.If REGISTER is not creating dialog then what is the
> importance of TO, FROM and call-id in REGISTER message?

See RFC 3261 section 10.2.
_______________________________________________
Sip-implementors mailing list
[email protected]
https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors

Reply via email to