30 Sep
2015
30 Sep
'15
10:19 a.m.
Hello,
Does anyone have experience with SIP and conntrackd?
Our media and signaling is separated.
Does this work for VPN connections where SIP is sent over the VPN but the media over
public internet?
Thanks,
Grant
30 Sep
30 Sep
11:56 a.m.
On Wednesday 30 September 2015 07:19:08 Grant Bagdasarian wrote:
Does anyone have experience with SIP and conntrackd?
Our media and signaling is separated.
Does this work for VPN connections where SIP is sent over the VPN but the
media over public internet?
I don't see the relation with conntrackd and your setup, unless you are using
some sip inspection to open the (local) rtp ports for specific
source/destinations. Which is a very bad idea IMHO, my experience is that any
of such ALG just cause more problems.
But if you use rtpengine and advertise the public ips in SDP the UAs will
contact them, the engine will learn the correct ipadress. It is up to routing
at the client to seperate the traffic correctly.
IIRC rtpproxy works the same.
4:07 p.m.
Yes, I understand.
Let me explain it like this and forget about VPN:
A phone call is set up from A to C through B.
A connects to B which in turn connects the call to C.
All traffic is sent using UDP over the public internet.
B has a firewall on both ends, so between A and B and B and C.
A is connected to C in say 10 seconds and they're exchanging RTP.
Now, the firewalls at B are turned off, or crash or whatever, mid call.
Would this cause the session to be disconnected? The media is obviously gone, but will the
session remain active?
I'm looking for a way to restore almost instantly in case of any failure, be it
firewall related.
My idea was to configure conntrackd on the firewalls which are setup in HA mode and where
a crash of the primary would result in a failover to the backup with full connection
restore.
-----Original Message-----
From: sr-users [mailto:sr-users-bounces@lists.sip-router.org] On Behalf Of Daniel Tryba
Sent: Wednesday, September 30, 2015 10:56 AM
To: sr-users(a)lists.sip-router.org
Subject: Re: [SR-Users] SIP and conntrackd experience?
On Wednesday 30 September 2015 07:19:08 Grant Bagdasarian wrote:
Does anyone have experience with SIP and conntrackd?
Our media and signaling is separated.
Does this work for VPN connections where SIP is sent over the VPN but
the media over public internet?
I don't see the relation with conntrackd and your setup, unless you are using some sip
inspection to open the (local) rtp ports for specific source/destinations. Which is a very
bad idea IMHO, my experience is that any of such ALG just cause more problems.
But if you use rtpengine and advertise the public ips in SDP the UAs will contact them,
the engine will learn the correct ipadress. It is up to routing at the client to seperate
the traffic correctly.
IIRC rtpproxy works the same.
_______________________________________________
SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list
sr-users(a)lists.sip-router.org
http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users
5:18 p.m.
On Wednesday 30 September 2015 13:07:12 Grant Bagdasarian wrote:
A is connected to C in say 10 seconds and they're
exchanging RTP.
Now, the firewalls at B are turned off, or crash or whatever, mid call.
Would this cause the session to be disconnected? The media is obviously
gone, but will the session remain active? I'm looking for a way to restore
almost instantly in case of any failure, be it firewall related.
My idea was to configure conntrackd on the firewalls which are setup in HA
mode and where a crash of the primary would result in a failover to the
backup with full connection restore.
As long as there is no additional signalling (DTMF over SIP INFO, session
timers, onhold events....) or endpoints detect the lack of RTP (or RTCP) after
a short timeout, the SIP session is still alive according to the endpoints.
So if RTP is only forwarded by the kernel (like the kernel forwarding
capabilities of rtpengine) and you could replicate these forwards to a standby
server, you could do a failover of both SIP and RTP. Theoretically...
If you are running rtpproxy, which actively accepts and forwards the RTP
traffic, you'd have to replicate the state of the proxy to a standby machine.
Which is AFAIK not possible.
1 Oct
1 Oct
10:35 a.m.
Alright, I understand. Thanks for explaining.
How do big carriers handle these kinds of scenarios where a sudden outage in a key
component would cause calls to be dropped?
Is this the achilles heel of voice? Is there special kind of software or hardware (or
both) for handling these kinds of scenarios?
-----Original Message-----
From: sr-users [mailto:sr-users-bounces@lists.sip-router.org] On Behalf Of Daniel Tryba
Sent: Wednesday, September 30, 2015 4:19 PM
To: sr-users(a)lists.sip-router.org
Subject: Re: [SR-Users] SIP and conntrackd experience?
On Wednesday 30 September 2015 13:07:12 Grant Bagdasarian wrote:
A is connected to C in say 10 seconds and they're
exchanging RTP.
Now, the firewalls at B are turned off, or crash or whatever, mid call.
Would this cause the session to be disconnected? The media is
obviously gone, but will the session remain active? I'm looking for a
way to restore almost instantly in case of any failure, be it firewall related.
My idea was to configure conntrackd on the firewalls which are setup
in HA mode and where a crash of the primary would result in a failover
to the backup with full connection restore.
As long as there is no additional signalling (DTMF over SIP INFO, session timers, onhold
events....) or endpoints detect the lack of RTP (or RTCP) after a short timeout, the SIP
session is still alive according to the endpoints.
So if RTP is only forwarded by the kernel (like the kernel forwarding capabilities of
rtpengine) and you could replicate these forwards to a standby server, you could do a
failover of both SIP and RTP. Theoretically...
If you are running rtpproxy, which actively accepts and forwards the RTP traffic,
you'd have to replicate the state of the proxy to a standby machine.
Which is AFAIK not possible.
_______________________________________________
SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list
sr-users(a)lists.sip-router.org
http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users
11:09 a.m.
On Thursday 01 October 2015 07:35:06 Grant Bagdasarian wrote:
How do big carriers handle these kinds of scenarios
where a sudden outage in
a key component would cause calls to be dropped? Is this the achilles heel
of voice? Is there special kind of software or hardware (or both) for
handling these kinds of scenarios?
See
http://www.ng-voice.com/redundancy-maxx/
for example.
Your specific concern:
"Both our deployed SEMS (thanks to the Frafos Team) and our deployed RTPEngine
(thanks to Carlos) use a Redis-Database for storing information on the current
calls, however in both cases through a proprietary extension. The Redis-
database is distributed among the two servers, so if we start the services on
the passive node, all sessions can continue without service interuption."
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