[asterisk-users] Asterisk H.323,
Cisco IOS Gatekeeper(s) intra-zone call routing and TETRA
Michael J. Tubby B.Sc. G8TIC
mike.tubby at thorcom.co.uk
Tue Feb 6 03:32:35 MST 2007
Stephan,
Ok, I'll re-state the problem...
I have two devices that I want to talk to each other:
1. an Asterisk PBX
2. a Damm Cellular TETRAFLEX digital radio system (www.damm.dk)
both devices are effectively "gateways" because they have many subscribers
behind them.
The Damm Cellular system controller is based on Windows-XP Embedded and its
sub-systems used the OpenH323 driver/libraries. Officially Damm supports
only H.323 connections and only to Innovaphone products such as IP phones
and ISDN gateways - I want to connect it to VoIP and Asterisk.
The Asterisk box is FC6, Asterisk 1.2.14, ooh323 from
Asterrisk-Addons-1.2.5 - using ooh323 because the others depend on OpenH323
libraries which are problematic (see below)
In the Damm Cellular system H.323 configuration use of a H.323 gatekeeper is
mandatory, not optional :o(
So, how to join the Damm system to an Asterisk box? Some ASCII art:
192.168.1.0/24
--------------------------------------------------------
| | |
192.168.1.7 192.168.1.6 192.168.1.5
| | |
---------------- ---------------- ----------------
| Damm Tetra | | Cisco Router | | Asterisk PBX |
| (OpenH323) | | GateKeeper | | (ooh323) |
| H323ID=DAMM | | Zone=THORCOM | | H323ID=PABX |
| Nos=817XXXX | | | | Nos=810XXXX |
---------------- ---------------- ----------------
I started on the hope of using the GNU GateKeeper 2.2.5 but ran into lots of
problems on my Fedora Core 6 box with libraries, incompatibilities,
compilation errors, the fact that OpenH323 appears deprecated in favour of
Opal, etc. and in the end gave up and switched to a spare Cisco 2621XM
router with c2600-jsx-mz.123-22.bin image which includes the Cisco H.323
Gatekeeper...
The I started reading the documentation and got entirely confused :o(
Nearly all of Cisco's examples show one gateway connected to one gatekeeper
in a local zone and may routes to other zones that are 'remote', ie. WAN
connected and all the traffic flow/examples appeared to be for this.
What I wanted/need is two gateways inside a single zone, and hence
intra-zone calling (not inter-zone) - confusion continued - because of the
talk of "technology prefixes" like "1#" and "2#" and "8#" ...
I already have a number plan/dial plan in the form 8EEXXXX where all of our
Asterisk exchanges have a two-digit exchange number, like "810", "820",
"867" etc. and we use four-digit extensions like 2001...2999 for phones,
6XXX for services like voicemail, etc. which makes it easy for work
collegues, friends and family to all have Asterisk exchanges and perform
inter-exchange dialling [yup, we have a hub/router asterisk box with loads
of IAX2 connections and no phones]
I assigned 817XXXX to the Damm TETRA system and my local PBX is already
810XXXX and is the only "route" to the rest of my 8EEXXXX number plan and to
the outside world.
I could see how the technology prefix could be used to route calls in the
H.323 context - for example i could declare Asterisk as technology 1# and
Tetra as 2# but while it is easy to add a leading 2# to dialled numbers
leaving the Asterisk box I could find no way to tell either the Damm system
or Asterisk which technology prefix to register -- this functionality
appears to be missing.
So, the question was - "how to route calls intra-zone without technology
prefixes" - back to the problem that there were plenty of examples of cross
site/inter-zone configurations but little about intra-zone - then last nigh
I stumbled on the phrase "in the updated version of the 'zone prefix'
command..." in Cisco IOS documentation, so I went and googled for "cisco ios
command reference zone prefix" and I think I may have found what I need...
So, I have the Damm system and Asterisk system both registered with the
Cisco GateKeeper as gateways:
router-h323-gw#show gatekeeper endpoints
GATEKEEPER ENDPOINT REGISTRATION
================================
CallSignalAddr Port RASSignalAddr Port Zone Name Type Flags
--------------- ----- --------------- ----- --------- ---- -----
192.168.1.5 1720 192.168.1.5 13030 THORCOM UNKN-GW
H323-ID: PABX
H323-ID: ASTERISK
E164-ID: 100
Voice Capacity Max.= Avail.= Current.= 0
192.168.1.7 1720 192.168.1.7 1085 THORCOM UNKN-GW
H323-ID: DAMM
Voice Capacity Max.= Avail.= Current.= 0
Total number of active registrations = 2
I've added the following zone prefixes to the Cisco gatekeeper config:
!
gatekeeper
zone local THORCOM int.thorcom.com 192.168.1.6
zone prefix THORCOM 0* gw-priority 5 PABX ! outside calls to PSTN
etc
zone prefix THORCOM 1* gw-priority 5 PABX ! calls to
information/operator
zone prefix THORCOM 2... gw-priority 5 PABX ! short calls to
extension numbers
zone prefix THORCOM 817.... gw-priority 10 DAMM ! calls to TETRA
zone prefix THORCOM 8...... gw-priority 5 PABX ! calls to rest of my
number plan
zone prefix THORCOM 9.. gw-priority 10 PABX ! emergency calls
911/999
gw-type-prefix 1#* default-technology
no shutdown
!
... so I think this should route the calls between the gateways...?
Mike
----- Original Message -----
From: "Stephen Bosch" <posting at vodacomm.ca>
To: "Michael J. Tubby G8TIC" <mike.tubby at thorcom.co.uk>
Sent: Monday, February 05, 2007 7:51 PM
Subject: Re: [asterisk-users] Help sought: Asterisk H.323, Cisco IOS
Gatekeeper(s) intra-zone call routing and TETRA
> Michael J. Tubby G8TIC wrote:
>> I can see how this be acheived if I had two Gatekeepers and two zones,
>> say one called "tetra" and one called "asterisk" by using zone prefixes
>> and "zone remote" to route between them and putting one of the gateways
>> on each of the Gatekeepers - but this appears to be over-the-top for
>> what I want, ie. two gateways on the same Gatekeeper at the same site,
>> in the same zone, routing calls between them...
>>
>>
>> Can anyone give me a clue where to go next with this?
>
> Oof... that was a lot to process.
>
> It's been a long time since I worked with H.323, but I'd be game to
> paddling about some ideas and see if I can provide any insight. I think
> your system is sufficiently complex that you're not likely to get a
> tonne of response from the list.
>
> I think the most confusing part of your plea is all the Cisco-specific
> stuff at the end. It's still not totally clear what you're trying to do.
> Can you try reframing it?
>
> -Stephen-
>
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