[asterisk-dev] Asterisks CSeq parsing not RFC 3261 compliant

[Raj Jain]

On Wed, Jun 11, 2008 at 5:55 AM, Tobias Engel <t-asterisk-dev at tobias.org> wrote:
> The registration failed, and after some tcpdumping I found out that
> Asterisk sends the following CSeq header:
>
> CSeq: 4 REGISTER
>
> and the CSeq header in the response by the BTS looks like this:
>
> CSeq: 4    REGISTER
>
> Asterisk fails to match that response to its request.

This gets even more interesting than that. Not only any can you have
tabs as whitespaces, SIP ABNF rules allow you to fold header lines.
For instance, the following is a valid header:

Cseq: 4
   REGISTER

The reality is that the current chan_sip doesn't really support proper
SIP ABNF parsing.

--
Raj Jain