Re: IP/VC 3520 migrating to MCM

Kevin Dorrell · ‎08-25-2005

I have an IP/VC 3520 gateway that we use for simple teleconferencing. It has three ISDN BRI connections that can be bundled to give up to 384 Kbps. The 3520 handles gatekeeper functions as well as the conversion between H.320 on the WAN side and H.323 on the LAN side.

As the 3520 is reaching EoL, I am trying to propose an alternative. Now, I may be barking up the the wrong tree, but it looked on paper that a 2650XM with H.323 MCM software would do the trick, with an ISDN primary rate NM installed. But I cannot get my head around the configuration.

So far, these are the relevant lines I have:

<b>

voice service voip

h323

!

interface FastEthernet0/0

ip address 192.168.4.5 255.255.255.0

h323-gateway voip bind srcaddr 192.168.4.5

!

interface Serial1/0:15

isdn switch-type primary-net5

h323-gateway voip interface

h323-gateway voip id gk5.mydomain.net ipaddr 192.168.4.5 1719

!

gateway

timer receive-rtp 1200

!

gatekeeper

zone local gk5 mydomain.net

no shut

!

</b>

At this point, I expected the gateway to register with the gatekeep, but it does not. A show gateway includes the messages:

H.323 service is up

This gateway is not registered to any gatekeeper.

Where do I start defining the services in the way I did in the 3520?

Or have I completely misunderstood the capabilities of this box? Sorry, I am a complete beginner when it comes to this stuff, and I seem to have go lost somewhere in the documentation. Help!

Kevin Dorrell

Luxembourg

Kevin Dorrell · ‎08-26-2005

Bump! H.323 MCM experts?

Vivek Bhargava · ‎08-27-2005

Hello Kevin,

You need a couple of other configuration commands on the GW - such as the GW h323-id, tech prefix, etc. You would also need to define some dial-peers so calls can be routed.

You should also move the config under the FE interface. For an example, please refer to:

http://www.cisco.com/en/US/tech/tk652/tk701/technologies_configuration_example09186a0080094ac3.shtml

Let me know if it still does not work for you.

Vivek Bhargava

kevinmcm · ‎08-28-2005

Hello Kevin,

Cisco IOS routers do not (yet) support H.320 bonding or any H.26x video codecs, so you cannot use them as a replacement for the IP/VC 35xx series gateways (if you want to do video calls...they do support audio-only calls though).

You're correct about the 3520 being end of sale. The replacement model for it is the 3521. See http://www.cisco.com/en/US/products/hw/video/ps1870/products_data_sheet09186a008010a81d.html for more info on it.

I believe the reason your IOS router is not registering with the gatekeeper is because you have the h.323-gateway voip commands mixed across two different interfaces (and you're missing a couple). Either move the bind srcaddr command down to the Serial1/0:15 interface, or move all of the h323-gateway commands up to the FA0/0 interface. Either way, you should also add the "h323-gateway voip h323-id interface-id" and the "h323-gateway voip tech-prefix prefix" commands to it as well.

Thanks,

Kevin McMenamy

Kevin Dorrell · ‎08-29-2005

Kevin,

Thanks for your posting, which I have been studying today. Particularly disappointed that the router cannot handle H.320 bonding on the ISDN side. That really puts it out of the field as far as this application is concerned. I am going to have an uphill struggle getting a 3521 (or a 3526) approved as it is quite expensive, and it will be in competition with a gateway from the suppliers of the VC equipment.

In your second posting you refer to the Serial 1/0:15 as a POTS interface, but that is not quite what I had understood by POTS. I though POTS referred to the old analog 2-wire phone connection. In this case, S1/0:15 is the D-channel of a primary rate ISDN. But I guess what you are saying is that the gatekeeper can use the interface to route Q931 voice calls, but not any fancy VC handling like H.320.

Nevertheless, while I have the box to play with, I would like to get some educational benefit from it, so I am still trying to get its gateway to talk to its gatekeeper. I have moved all the h323 to the F0/0 as you suggested, and added a couple of tech-prefixes for good measure. But I still do ne see it registering. (BTW, yes the interface is up). Here is the (stripped) config I have:

teleconf-cisco#show run

Building configuration...

Current configuration : 1985 bytes

!

version 12.3

service timestamps debug datetime msec

service timestamps log datetime msec

no service password-encryption

!

hostname teleconf-cisco

!

ip domain name mydomain.net

!

isdn switch-type primary-net5

!

voice service voip

h323

!

interface Loopback0

ip address 192.168.9.1 255.255.255.0

!

interface FastEthernet0/0

ip address 192.168.4.5 255.255.255.0

no ip route-cache

duplex auto

speed auto

h323-gateway voip interface

h323-gateway voip id gk5 ipaddr 192.168.4.5 1719

h323-gateway voip h323-id GW5

h323-gateway voip tech-prefix 81#

h323-gateway voip tech-prefix 82#

h323-gateway voip tech-prefix 83#

h323-gateway voip bind srcaddr 192.168.4.5

!

interface Serial1/0:15

ip unnumbered FastEthernet0/0

no ip route-cache

isdn switch-type primary-net5

no cdp enable

!

ip default-gateway 192.168.4.254

ip http server

ip classless

!

control-plane

!

gateway

timer receive-rtp 1200

!

gatekeeper

zone local gk5 mydomain.net

no shutdown

!

end

But I still cannet get it to register:

teleconf-cisco#show gateway

H.323 ITU-T Version: 4.0 H323 Stack Version: 0.1

H.323 service is up

Gateway GW5 is not registered to any gatekeeper

Alias list (CLI configured)

H323-ID GW5

Alias list (last RCF) is empty

H323 resource thresholding is Disabled

teleconf-cisco#

Can you see where I am going wrong? I have tried shutting and no-shutting the gateway.

Thanks in advance.

Kevin Dorrell

Luxembourg

kevinmcm · ‎08-29-2005

Hi Kevin,

I'm not 100% sure, but I think it may be because you have to bind the gatekeeper to the FA0/0 interface as well (since that is what your using in your h323-gateway voip id command). To do this, the IP address of the interface that you want the gatekeeper to be bound to needs to be entered at the end of the zone local command, such as "zone local gk5 mydomain.net 192.168.4.5"

You can use debug h225 asn1 to see the messages between the gateway and the gatekeeper.

I didn't mean to suggest that the Serial interface was actually a POTS port. I meant to say that you had it configured as a voice port, and hence cannot be assigned an IP address or have the h323-gateway function bound to it, but if you're using it as a data port and not a voice port than I was wrong. In your initial config you didn't have any ip address assigned to it (now you have ip unnumbered on it) so I assumed it was a voice port...

Kev

Kevin Dorrell · ‎08-30-2005

Kevin,

OK, I have got the gateway to register with the gatekeeper now. You know what the problem was? .... the loopback interface. I tried the debug as you suggested, and saw something about "C0A80901" which I recognised as 192.168.9.1. I had only expected to see 192.168.4.5, if anything. Got rid of the loopback interface, and it registered. Now I have to work out what it all means!

Thanks for you help. No doubt I will have more question in a few days time.

Kevin Dorrell

Luxembourg

kevinmcm · ‎08-30-2005

Ya, probably the gatekeeper was trying to respond from the loopback interface instead of from the FA0/0 interface. By deleting the loopback interface, or by binding the gatekeeper to the FA0/0 interface (by specifying it at the end of the zone local command) would fix that.

Kev

kevinmcm · ‎08-28-2005

Actually, my applogies. You cannot use the Serial1/0:15 interface as an H.323 interface. This is a POTS interface. You should move all your h323-gateway commands up to your FA0/0 interface.