Hello all, In our deployments, Freeswitch is on a public IP with most user endpoints behind NAT. As the demand for BLFs has grown I've been forced to go to TCP due the NOTIFYs exceeding MTU. I've been reluctant to use TCP for SIP due to the increased overhead. Currently I force a registration expiry of 600 seconds and ping all NATed endpoints. I'm exploring the idea of switching all endpoints to TCP where available, ditching the options pings and dropping the registration expiration to 300 secs which should exceed the TCP connection timeout of almost every router I've seen. I was currious if anyone had an experience or could point out any caveats I might run into. Thanks in advance, Spencer
On a Linux system there is a limit of how many open TCP connections you have. Unless you have a crazy amount of endpoints you have to serve, TCP probably isn’t really worth it in my opinion. Also did I also mention that TCP connections don’t really fix NAT issues? From: freeswitch-users-bounces@lists.freeswitch.org [mailto:freeswitch-users-bounces@lists.freeswitch.org] On Behalf Of Spencer Thomason Sent: Wednesday, May 8, 2013 8:31 AM To: FreeSWITCH Users Help Subject: [Freeswitch-users] TCP vs UDP SIP Hello all, In our deployments, Freeswitch is on a public IP with most user endpoints behind NAT. As the demand for BLFs has grown I've been forced to go to TCP due the NOTIFYs exceeding MTU. I've been reluctant to use TCP for SIP due to the increased overhead. Currently I force a registration expiry of 600 seconds and ping all NATed endpoints. I'm exploring the idea of switching all endpoints to TCP where available, ditching the options pings and dropping the registration expiration to 300 secs which should exceed the TCP connection timeout of almost every router I've seen. I was currious if anyone had an experience or could point out any caveats I might run into. Thanks in advance, Spencer
In my opinion, TCP seems better than UDP as you know all the SIP packets are making to their destination. On Wed, May 8, 2013 at 11:37 AM, Jeff Leung <jleung@v10networks.ca> wrote:
On a Linux system there is a limit of how many open TCP connections you have.
I never heard this before...where and how it this limit defined?
Unless you have a crazy amount of endpoints you have to serve, TCP probably isn’t really worth it in my opinion.
How many endpoints?
Also did I also mention that TCP connections don’t really fix NAT issues?
-----Original Message----- From: freeswitch-users-bounces@lists.freeswitch.org [mailto:freeswitch- users-bounces@lists.freeswitch.org] On Behalf Of Vik Killa Sent: Wednesday, May 8, 2013 9:18 AM To: FreeSWITCH Users Help Subject: Re: [Freeswitch-users] TCP vs UDP SIP
That I would agree with, but the thing is you lose the capability of failover in the unlikely event that a node in a FreeSWITCH cluster fail.
In my opinion, TCP seems better than UDP as you know all the SIP packets are making to their destination.
On Wed, May 8, 2013 at 11:37 AM, Jeff Leung <jleung@v10networks.ca> wrote:
On a Linux system there is a limit of how many open TCP connections you have.
If I can remember correctly, I think Darren from 2600hz did discuss about the limit of open TCP connections you can have on a Linux system. Correct me if I'm wrong on this, but that seems to be the case. And I have seen instances of that happening on a misconfigured Squid Proxy
I never heard this before...where and how it this limit defined?
Unless you have a crazy amount of endpoints you have to serve, TCP probably isn't really worth it in my opinion.
Assuming it's one Open TCP connection per endpoint, you'd probably need more endpoints than the maximum amount of open TCP connections to hit that problem
How many endpoints?
Also did I also mention that TCP connections don't really fix NAT issues?
Hi Jeff, Thanks for the insight. Forgive my ignorance but if I have two Identical Freeswitch servers with SRV records and endpoints that properly support SRVs, why do I loose the ability to failover if one host is not reachable? Also as many of these end points are Polycoms behind NAT, I can't see any reason I'd still need NDLB-force-rport on the profile? Since these are application servers, handling conferences, presence, etc., I'd imagine I would hit other bottlenecks before I hit the TCP connection limit. On May 8, 2013, at 9:51 AM, "Jeff Leung" <jleung@v10networks.ca> wrote:
-----Original Message----- From: freeswitch-users-bounces@lists.freeswitch.org [mailto:freeswitch- users-bounces@lists.freeswitch.org] On Behalf Of Vik Killa Sent: Wednesday, May 8, 2013 9:18 AM To: FreeSWITCH Users Help Subject: Re: [Freeswitch-users] TCP vs UDP SIP
That I would agree with, but the thing is you lose the capability of failover in the unlikely event that a node in a FreeSWITCH cluster fail.
In my opinion, TCP seems better than UDP as you know all the SIP packets are making to their destination.
On Wed, May 8, 2013 at 11:37 AM, Jeff Leung <jleung@v10networks.ca> wrote:
On a Linux system there is a limit of how many open TCP connections you have.
If I can remember correctly, I think Darren from 2600hz did discuss about the limit of open TCP connections you can have on a Linux system. Correct me if I'm wrong on this, but that seems to be the case. And I have seen instances of that happening on a misconfigured Squid Proxy
I never heard this before...where and how it this limit defined?
Unless you have a crazy amount of endpoints you have to serve, TCP probably isn't really worth it in my opinion.
Assuming it's one Open TCP connection per endpoint, you'd probably need more endpoints than the maximum amount of open TCP connections to hit that problem
How many endpoints?
Also did I also mention that TCP connections don't really fix NAT issues?
_________________________________________________________________________ Professional FreeSWITCH Consulting Services: consulting@freeswitch.org http://www.freeswitchsolutions.com
FreeSWITCH-powered IP PBX: The CudaTel Communication Server http://www.cudatel.com
Official FreeSWITCH Sites http://www.freeswitch.org http://wiki.freeswitch.org http://www.cluecon.com
FreeSWITCH-users mailing list FreeSWITCH-users@lists.freeswitch.org http://lists.freeswitch.org/mailman/listinfo/freeswitch-users UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users http://www.freeswitch.org
Hi Jeff, Thanks for the insight. Forgive my ignorance but if I have two Identical Freeswitch servers with SRV records and endpoints that properly support SRVs, why do I loose the ability to failover if one host is not reachable?
TCP is a stateful protocol. On the other hand UDP isn't, it's stateless. It's just easier to failover with UDP than with TCP if you understand the difference between the two protocols. I'm not saying that it's not possible to do so with TCP, but with the way how SIP works, you'd want to use UDP if you want failover capabilities without the headache.
Also as many of these end points are Polycoms behind NAT, I can't see any reason I'd still need NDLB-force-rport on the profile?
Unfortunately, I don't work with Polycom phones. Brian West over here can comment on that issue.
Since these are application servers, handling conferences, presence, etc., I'd imagine I would hit other bottlenecks before I hit the TCP connection limit.
Yes that's true, but if you had a FreeSWITCH box that purely handled SIP messages and no media, you'd probably hit that TCP Open connection limit.
On May 8, 2013, at 9:51 AM, "Jeff Leung" <jleung@v10networks.ca> wrote:
-----Original Message----- From: freeswitch-users-bounces@lists.freeswitch.org [mailto:freeswitch- users-bounces@lists.freeswitch.org] On Behalf Of Vik Killa Sent: Wednesday, May 8, 2013 9:18 AM To: FreeSWITCH Users Help Subject: Re: [Freeswitch-users] TCP vs UDP SIP
That I would agree with, but the thing is you lose the capability of failover in the unlikely event that a node in a FreeSWITCH cluster fail.
In my opinion, TCP seems better than UDP as you know all the SIP packets are making to their destination.
On Wed, May 8, 2013 at 11:37 AM, Jeff Leung <jleung@v10networks.ca> wrote:
On a Linux system there is a limit of how many open TCP connections you have.
If I can remember correctly, I think Darren from 2600hz did discuss about the limit of open TCP connections you can have on a Linux system. Correct me if I'm wrong on this, but that seems to be the case. And I have seen instances of that happening on a misconfigured Squid Proxy
I never heard this before...where and how it this limit defined?
Unless you have a crazy amount of endpoints you have to serve, TCP probably isn't really worth it in my opinion.
Assuming it's one Open TCP connection per endpoint, you'd probably need more endpoints than the maximum amount of open TCP connections
to
hit that problem
How many endpoints?
Also did I also mention that TCP connections don't really fix NAT issues?
__________________________________________________________ ____________
___ Professional FreeSWITCH Consulting Services: consulting@freeswitch.org http://www.freeswitchsolutions.com
FreeSWITCH-powered IP PBX: The CudaTel Communication Server http://www.cudatel.com
Official FreeSWITCH Sites http://www.freeswitch.org http://wiki.freeswitch.org http://www.cluecon.com
FreeSWITCH-users mailing list FreeSWITCH-users@lists.freeswitch.org http://lists.freeswitch.org/mailman/listinfo/freeswitch-users UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-use rs http://www.freeswitch.org
__________________________________________________________ _______________ Professional FreeSWITCH Consulting Services: consulting@freeswitch.org http://www.freeswitchsolutions.com
FreeSWITCH-powered IP PBX: The CudaTel Communication Server http://www.cudatel.com
Official FreeSWITCH Sites http://www.freeswitch.org http://wiki.freeswitch.org http://www.cluecon.com
FreeSWITCH-users mailing list FreeSWITCH-users@lists.freeswitch.org http://lists.freeswitch.org/mailman/listinfo/freeswitch-users UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users http://www.freeswitch.org
Understood. My plan is to use UDP for all "trunking" type endpoints at TCP for desk phones as they will likely receive more NOTIFYs and in most cases being behind NAT where the longer connection timeout comes in handy. I also found a good paper on the subject: http://www.cs.columbia.edu/~kumiko/publish/IPTComm08_paper.pdf In regard to connection timeout how does Freeswitch handle this? I noticed the new Sofia parameters and I was curious if the connection lifetime was configurable as well. BR, Spencer On May 8, 2013, at 10:20 AM, "Jeff Leung" <jleung@v10networks.ca> wrote:
Hi Jeff, Thanks for the insight. Forgive my ignorance but if I have two Identical Freeswitch servers with SRV records and endpoints that properly support SRVs, why do I loose the ability to failover if one host is not reachable?
TCP is a stateful protocol. On the other hand UDP isn't, it's stateless. It's just easier to failover with UDP than with TCP if you understand the difference between the two protocols. I'm not saying that it's not possible to do so with TCP, but with the way how SIP works, you'd want to use UDP if you want failover capabilities without the headache.
Also as many of these end points are Polycoms behind NAT, I can't see any reason I'd still need NDLB-force-rport on the profile?
Unfortunately, I don't work with Polycom phones. Brian West over here can comment on that issue.
Since these are application servers, handling conferences, presence, etc., I'd imagine I would hit other bottlenecks before I hit the TCP connection limit.
Yes that's true, but if you had a FreeSWITCH box that purely handled SIP messages and no media, you'd probably hit that TCP Open connection limit.
On May 8, 2013, at 9:51 AM, "Jeff Leung" <jleung@v10networks.ca> wrote:
-----Original Message----- From: freeswitch-users-bounces@lists.freeswitch.org [mailto:freeswitch- users-bounces@lists.freeswitch.org] On Behalf Of Vik Killa Sent: Wednesday, May 8, 2013 9:18 AM To: FreeSWITCH Users Help Subject: Re: [Freeswitch-users] TCP vs UDP SIP
That I would agree with, but the thing is you lose the capability of failover in the unlikely event that a node in a FreeSWITCH cluster fail.
In my opinion, TCP seems better than UDP as you know all the SIP packets are making to their destination.
On Wed, May 8, 2013 at 11:37 AM, Jeff Leung <jleung@v10networks.ca> wrote:
On a Linux system there is a limit of how many open TCP connections you have.
If I can remember correctly, I think Darren from 2600hz did discuss about the limit of open TCP connections you can have on a Linux system. Correct me if I'm wrong on this, but that seems to be the case. And I have seen instances of that happening on a misconfigured Squid Proxy
I never heard this before...where and how it this limit defined?
Unless you have a crazy amount of endpoints you have to serve, TCP probably isn't really worth it in my opinion.
Assuming it's one Open TCP connection per endpoint, you'd probably need more endpoints than the maximum amount of open TCP connections
to
hit that problem
How many endpoints?
Also did I also mention that TCP connections don't really fix NAT issues?
____________
___ Professional FreeSWITCH Consulting Services: consulting@freeswitch.org http://www.freeswitchsolutions.com
FreeSWITCH-powered IP PBX: The CudaTel Communication Server http://www.cudatel.com
Official FreeSWITCH Sites http://www.freeswitch.org http://wiki.freeswitch.org http://www.cluecon.com
FreeSWITCH-users mailing list FreeSWITCH-users@lists.freeswitch.org http://lists.freeswitch.org/mailman/listinfo/freeswitch-users UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-use rs http://www.freeswitch.org
__________________________________________________________ _______________ Professional FreeSWITCH Consulting Services: consulting@freeswitch.org http://www.freeswitchsolutions.com
FreeSWITCH-powered IP PBX: The CudaTel Communication Server http://www.cudatel.com
Official FreeSWITCH Sites http://www.freeswitch.org http://wiki.freeswitch.org http://www.cluecon.com
FreeSWITCH-users mailing list FreeSWITCH-users@lists.freeswitch.org http://lists.freeswitch.org/mailman/listinfo/freeswitch-users UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users http://www.freeswitch.org
_________________________________________________________________________ Professional FreeSWITCH Consulting Services: consulting@freeswitch.org http://www.freeswitchsolutions.com
FreeSWITCH-powered IP PBX: The CudaTel Communication Server http://www.cudatel.com
Official FreeSWITCH Sites http://www.freeswitch.org http://wiki.freeswitch.org http://www.cluecon.com
FreeSWITCH-users mailing list FreeSWITCH-users@lists.freeswitch.org http://lists.freeswitch.org/mailman/listinfo/freeswitch-users UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users http://www.freeswitch.org
I've come across difficulties with TCP and NAT. Some NAT implementations do not allow new connections from the PBX to the phone through the NAT and there's no requirement to reuse and existing, long-lived TCP connection. Some notifications and invites can get blocked unnecessarily. On 8 May 2013 19:13, Spencer Thomason <spencer@5ninesolutions.com> wrote:
Understood. My plan is to use UDP for all "trunking" type endpoints at TCP for desk phones as they will likely receive more NOTIFYs and in most cases being behind NAT where the longer connection timeout comes in handy. I also found a good paper on the subject: http://www.cs.columbia.edu/~kumiko/publish/IPTComm08_paper.pdf
In regard to connection timeout how does Freeswitch handle this? I noticed the new Sofia parameters and I was curious if the connection lifetime was configurable as well.
BR, Spencer
On May 8, 2013, at 10:20 AM, "Jeff Leung" <jleung@v10networks.ca> wrote:
Hi Jeff,
Thanks for the insight. Forgive my ignorance but if I have two Identical
Freeswitch servers with SRV records and endpoints that properly support
SRVs, why do I loose the ability to failover if one host is not reachable?
TCP is a stateful protocol. On the other hand UDP isn't, it's stateless. It's just easier to failover with UDP than with TCP if you understand the difference between the two protocols. I'm not saying that it's not possible to do so with TCP, but with the way how SIP works, you'd want to use UDP if you want failover capabilities without the headache.
Also as many of these end points are Polycoms behind NAT, I can't see any
reason I'd still need NDLB-force-rport on the profile?
Unfortunately, I don't work with Polycom phones. Brian West over here can comment on that issue.
Since these are application servers, handling conferences, presence, etc.,
I'd
imagine I would hit other bottlenecks before I hit the TCP connection
limit.
Yes that's true, but if you had a FreeSWITCH box that purely handled SIP messages and no media, you'd probably hit that TCP Open connection limit.
On May 8, 2013, at 9:51 AM, "Jeff Leung" <jleung@v10networks.ca> wrote:
-----Original Message-----
From: freeswitch-users-bounces@lists.freeswitch.org
[mailto:freeswitch- users-bounces@lists.freeswitch.org] On Behalf Of
Vik Killa
Sent: Wednesday, May 8, 2013 9:18 AM
To: FreeSWITCH Users Help
Subject: Re: [Freeswitch-users] TCP vs UDP SIP
That I would agree with, but the thing is you lose the capability of
failover in the unlikely event that a node in a FreeSWITCH cluster fail.
In my opinion, TCP seems better than UDP as you know all the SIP
packets are making to their destination.
On Wed, May 8, 2013 at 11:37 AM, Jeff Leung <jleung@v10networks.ca>
wrote:
On a Linux system there is a limit of how many open TCP
connections you have.
If I can remember correctly, I think Darren from 2600hz did discuss
about the limit of open TCP connections you can have on a Linux
system. Correct me if I'm wrong on this, but that seems to be the
case. And I have seen instances of that happening on a misconfigured
Squid Proxy
I never heard this before...where and how it this limit defined?
Unless you have a crazy amount of endpoints you have to serve, TCP
probably isn't really worth it in my opinion.
Assuming it's one Open TCP connection per endpoint, you'd probably
need more endpoints than the maximum amount of open TCP connections
to
hit that problem
How many endpoints?
Also did I also mention that TCP connections don't really fix NAT
issues?
__________________________________________________________
____________
___ Professional FreeSWITCH Consulting Services:
consulting@freeswitch.org
http://www.freeswitchsolutions.com
FreeSWITCH-powered IP PBX: The CudaTel Communication Server
Official FreeSWITCH Sites
FreeSWITCH-users mailing list
FreeSWITCH-users@lists.freeswitch.org
http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-use
rs
__________________________________________________________
_______________
Professional FreeSWITCH Consulting Services:
consulting@freeswitch.org
http://www.freeswitchsolutions.com
FreeSWITCH-powered IP PBX: The CudaTel Communication Server
Official FreeSWITCH Sites
FreeSWITCH-users mailing list
FreeSWITCH-users@lists.freeswitch.org
http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
_________________________________________________________________________ Professional FreeSWITCH Consulting Services: consulting@freeswitch.org http://www.freeswitchsolutions.com
FreeSWITCH-powered IP PBX: The CudaTel Communication Server http://www.cudatel.com
Official FreeSWITCH Sites http://www.freeswitch.org http://wiki.freeswitch.org http://www.cluecon.com
FreeSWITCH-users mailing list FreeSWITCH-users@lists.freeswitch.org http://lists.freeswitch.org/mailman/listinfo/freeswitch-users UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users http://www.freeswitch.org
_________________________________________________________________________ Professional FreeSWITCH Consulting Services: consulting@freeswitch.org http://www.freeswitchsolutions.com
FreeSWITCH-powered IP PBX: The CudaTel Communication Server http://www.cudatel.com
Official FreeSWITCH Sites http://www.freeswitch.org http://wiki.freeswitch.org http://www.cluecon.com
FreeSWITCH-users mailing list FreeSWITCH-users@lists.freeswitch.org http://lists.freeswitch.org/mailman/listinfo/freeswitch-users UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users http://www.freeswitch.org
-- *Andrew Cassidy BSc (Hons) MBCS SSCA* Managing Director *T <info@cassidywebservices.co.uk> *03300 100 960 *F<info@cassidywebservices.co.uk> *03300 100 961 *E <info@cassidywebservices.co.uk> *andrew@cassidywebservices.co.uk *W <info@cassidywebservices.co.uk> *www.cassidywebservices.co.uk
participants (4)
-
Andrew Cassidy
-
Jeff Leung
-
Spencer Thomason
-
Vik Killa