H.323 Gateway redundancy

[Guest]

Archived from groups: comp.dcom.voice-over-ip (More info?)

Hello,
I'm about to deploy a softswitch based VoIP service and I would like
to get some opinions about the following issue:
is it possible configure two H.323 gateways (each with a different IP
address) in a redundant solution - so when one gateway fails - the
established calles will be handled by the other gateway without
disconnecting?
as far as i know (and according to some vendors) it is not possible,
due to the fact that H.225/H.245 connections that Gateway A had
established cannot be taken over by Gateway B.
all comments will be appreciated.

Joei.

 

[Guest]

Archived from groups: comp.dcom.voice-over-ip (More info?)

Hi,
The best way is to go through Gatekeeper. The Gatekeeper(GK) can
monitor the Gws and reroute . But the question is if GK fails what is
the solution?. Telecom require 99.9999 up time you can configure your
network with two GKs. All these leads to high cost and complexity.
If the network is small and only for your internal communications you
can just go with Gws and it is highly reliable.

appan kh






dotcommune@hotmail.com (Joei valley) wrote in message news:<db3c224e.0406010646.23fe99@posting.google.com>...
> Hello,
> I'm about to deploy a softswitch based VoIP service and I would like
> to get some opinions about the following issue:
> is it possible configure two H.323 gateways (each with a different IP
> address) in a redundant solution - so when one gateway fails - the
> established calles will be handled by the other gateway without
> disconnecting?
> as far as i know (and according to some vendors) it is not possible,
> due to the fact that H.225/H.245 connections that Gateway A had
> established cannot be taken over by Gateway B.
> all comments will be appreciated.
>
> Joei.

 

[Guest]

Archived from groups: comp.dcom.voice-over-ip (More info?)

Thanks for your comment,
The problem is that the GK can only redirect new unestablished calls
(in response to ARQ/LRQ messages received *after* one of the GWs have
failed) to the other GW - and my concern is about calls that have been
already established to one of the GW, can they be somehow redirected
to another H.323 endpoint without disconnecting the call?
Please note that in my scenario the 'GW' is actually two separate
machines (and IP) - one handles H.225/H.245 signalling and the other
handles the RTP and provides the TDM interface.

Joei.

appan@btinternet.com (Appan KH) wrote in message news:<3f49bb18.0406020327.111d9d7e@posting.google.com>...
> Hi,
> The best way is to go through Gatekeeper. The Gatekeeper(GK) can
> monitor the Gws and reroute . But the question is if GK fails what is
> the solution?. Telecom require 99.9999 up time you can configure your
> network with two GKs. All these leads to high cost and complexity.
> If the network is small and only for your internal communications you
> can just go with Gws and it is highly reliable.
>
> appan kh
>
>
>
>
>
>
> dotcommune@hotmail.com (Joei valley) wrote in message news:<db3c224e.0406010646.23fe99@posting.google.com>...
> > Hello,
> > I'm about to deploy a softswitch based VoIP service and I would like
> > to get some opinions about the following issue:
> > is it possible configure two H.323 gateways (each with a different IP
> > address) in a redundant solution - so when one gateway fails - the
> > established calles will be handled by the other gateway without
> > disconnecting?
> > as far as i know (and according to some vendors) it is not possible,
> > due to the fact that H.225/H.245 connections that Gateway A had
> > established cannot be taken over by Gateway B.
> > all comments will be appreciated.
> >
> > Joei.

 

[Guest]

Archived from groups: comp.dcom.voice-over-ip (More info?)

Joei valley wrote:
>
> is it possible configure two H.323 gateways (each with a different IP
> address) in a redundant solution - so when one gateway fails - the
> established calles will be handled by the other gateway without
> disconnecting?

As I understand it, this is difficult for H.323 because of its use of
TCP signaling channels. The concept of migrating connected TCP sockets
to another system is pretty challenging - the packet sequence numbers
are nearly impossible to synchronize. If you can't maintain the control
channels, I think you lose the call.

I don't know of all the possible solutions - there are probably
different ways of approaching the problem that could lead to a high
availability system.

On the other hand, SIP signaling and RTP media streams can be (and have
been) made workable in a redundant configuration.

-Scott