[SR-Users] Loose Routing with Cisco router

[David Wilson]

Alex,
Thanks.  It's good to know that it should work.


Daniel,
It's a 2811 running IOS 12.4(25g).

>> [a] ===> [kamailio] ===> [cisco] ===> [b]
This is exactly what I need.  I'm trying to modify the request at [kamailio] so that [cisco] forwards to [b].

Possible complication is that [cisco] is also configured as a voice gateway with a SIP trunk to an external provider and a Call manager on the inside.  However, this is independent SIP traffic that [cisco] appears to try to route according to voice rules.

I can get the call to proceed by adding a dial-peer to [cisco] config, but if I have understood loose-routing, that shouldn't be necessary.

I have tried several combinations of header and r-URI modifications to test [cisco]'s behaviour, including Route:[cisco];lr  but it still seems to respond to the r-uri in the way I initially described.

All the best,
Dave  


On 14 Aug 2013, at 5:09 pm, sr-users-request at lists.sip-router.org wrote:

> 
> 
> Message: 3
> Date: Wed, 14 Aug 2013 13:06:19 +0400
> From: Alex Balashov <abalashov at evaristesys.com>
> To: miconda at gmail.com,	"Kamailio (SER) - Users Mailing List"
> 	<sr-users at lists.sip-router.org>
> Subject: Re: [SR-Users] Loose Routing with Cisco router
> Message-ID: <65a98f42-c370-49fe-91c4-d018b3d61249 at email.android.com>
> Content-Type: text/plain; charset=UTF-8
> 
> I use Kamailio extensively with Cisco AS5xxx series gateways and they have never had a problem dealing with Kamailio's RRs and lr values. 
> 
> 
> Daniel-Constantin Mierla <miconda at gmail.com> wrote:
>> Hello,
>> 
>> what model the cisco router is?
>> 
>> From what I understand, you want to go from:
>> 
>> [a] ===> [kamailio] ===> [b]
>> 
>> to:
>> 
>> [a] ===> [kamailio] ===> [cisco] ===> [b]
>> 
>> The usual will be that kamailio sets the r-uri to [b] and dsturi 
>> (outbound proxy) to [cisco] and then relay. The cisco should have some 
>> config options just to forward the traffic based on r-uri, however I 
>> never had to deal cisco configs. Maybe you add a Route header with 
>> [cisco];lr, then it should match itself in the route header and send to
>> 
>> r-uri.
>> 
>> On the other hand, when I had to interoperate with cisco
>> gateways/b2bua, 
>> they had no problem understanding loose routing added by kamailio.
>> 
>> Cheers,
>> Daniel
>> 
>> On 8/13/13 10:05 AM, David Wilson wrote:
>>> Hello All,
>>> 
>>> I'm running Kamailio 4.0.2 on Ubuntu 12.04 (precise).
>>> 
>>> I have SIP messaging flowing nicely, with UACs registering via
>> Kamailio (as a proxy) to a Registrar.
>>> 
>>> Now having problems trying to route messages via a Cisco router
>> (12.4(25g)) using loose routing.  The plan is to allow the router to
>> see the SIP messaging but forward it to the original location.
>>> 
>>> RFC 3261 seems to cover this case in Section 16.6 part 6: "A proxy
>> MAY have a local policy that mandates that a request visit a specific
>> set of proxies before being delivered to the destination."
>>> 
>>> Cisco documentation (SIP Configuration Guide, Cisco IOS Release 12.4)
>> states that it implements RFC 3261, including Loose-routing.   However,
>> from my observation the router doesn't like a request-URI with anything
>> other than its own IP address (it returns 400 Bad Request - 'Invalid IP
>> address'), but with any attempt to 'decorate' the URI with lr and/or
>> maddr= parameters it returns 400 Bad Request - 'Malformed/Missing' URL.
>> One of these messages is returned regardless of anything I've tried
>> with Via, Record-Route or Route headers.
>>> 
>>> Desired behaviour is for the router to remain in the route-set.  A
>> different configuration has shown me that this will achieve the
>> required outcome, the tricky part now is just getting that first
>> request to route.  I know several ways to make Kamailio send to the
>> router, but the router is not behaving as I expect when I preload a
>> route set (with Route: headers).
>>> 
>>> Recognising that this is probably more of a Cisco problem than
>> Kamailio, can anyone confirm whether a Cisco router implements
>> loose-routing when receiving messages, or only when sending?
>>> 
>>> Regards,
>>> Dave.
>>> 
>>> 
>>> _______________________________________________
>>> SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing
>> list
>>> sr-users at lists.sip-router.org
>>> http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users
> 
> --
> Sent from my mobile, and thus lacking in the refinement one might expect from a fully fledged keyboard. 
> 
> Alex Balashov - Principal
> Evariste Systems LLC
> 235 E Ponce de Leon Ave
> Suite 106
> Decatur, GA 30030
> United States
> Tel: +1-678-954-0670
> Web: http://www.evaristesys.com/, http://www.alexbalashov.com
> 
> 
> 

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