Modifying SIP OPTIONS header: TO

Hi there community,

I hope that who is reading this is fine,
About this topic, I’m trying to get a SIP 200 from a Supplier who validates SIP TO in their SIP OPTIONS inbound requests.

Currently I receive SIP 404 since the system sends SIP TO: sip:SupplierIP
And I should send
To: sip:Prefix@SupplierIP

I couldn’t find any information and maybe there is no way to do it, but I’m asking for help anyways

Any advice or commentary will be appreciated
Kind Regards

Why do you need a 200 OK? Asterisk doesn’t care.

Hi @jcolp
Thanks for the fast reply,
I’m trying to discard a Supplier behavior, whereas he doesn’t reply some SIP OPTIONS requests,
Maybe because their system architecture drops some packets after certain SIP 404 replies

Hope you get the idea

You’ll need to specify which SIP channel driver you are using then.

I’m using chan sip with the supplier

If I understand you correctly, calls work, but you only get a bad reply to OPTIONS request. Is that right? The reason I ask is because I’ve seen SIP-service providers where OPTIONS requests are never answered (which makes some sense).

What do you mean with “the system” in your first post? Is it your PBX, or the provider’s telephony server? You could show us a SIP trace of such a transaction (request and reply).

Hi there @EkFudrek

The “issue” is that the Telephony Supplier sometimes doesn’t reply to SIP OPTIONS, maybe that is because I keep sending “Wrong” (For the Supplier) SIP OPTION headers so, eventually the Supplier doesn’t listen to my SIP OPTIONS requests.

By System i meant my Asterisk server

Thanks for your reply

I don’t see any abbreviated TO headers on my systems, but I use only PJSIP. Sometimes you must allow your OPTIONS request to authorize. chan_pjsip has an option for this. If you have a larger nonce lifetime and if that is supported, you see authorizations only now and then. Please paste a SIP trace.

If it happens “sometimes”, it could be that they switch servers and that these servers have slightly different configurations. HOMER would be your friend to check things like that with a minimum of effort…