MGCP vs. H.323

[oconnost]

We are in the process of developing a VOIP network. The architecture will have roughly 10 sites with various voice/date apps. including Voice, Fax while using Unity for Unified Messaging. I

We are not sure whether the use 6608's with MGCP or AS5350/AS5400's with MGCP or H.323.

I may not have provided enough information to start this discussion, but would like to know;

- thoughts

- More H.323 or MGCP deployed networks

- Will MGCP or H.323 provide better features..

- I assume MGCP is easier to deploy ????

- The better protocol for future growth..

- More......

All opinions are appreciated..

Thanks,

Steve

[Niels Brunsgaard]

This is somewhat of a religious discussion, but at the highest level I would say that:

-MGCP is simpler to administer as the dialplan resides solely on Call Manager

-With H.323 the dialplan is split across Call Manager and gateway, so harder to administer. But also more flexible as you can take advantage of the huge range of IOS features (digit translation, ISDN options, etc).

95% of the worlds VoIP traffic uses H332. Also, AS5350/5400 work with CallManager only in H323 mode and not MGCP.

[oconnost]

I appreciate your response. However I have noticed that Cisco supports H.323 V2 & V3... As well, the AS5400 documentation indicates the 5400 supports MGCP, H.323 and SIP.. Are you saying that the 5400's will not work with CallManager ??

Is CallManager used in the call setup for H.323... The Cisco docs do not identify the CallManager in the call setup, instead they refer to communicating to the gatway and gatekeeper.. Please help clear this up for me...

Thanks for all your help..

Steve

[Niels Brunsgaard]

MGCP and Call Manager MGCP are slightly different. With CCM MGCP the ISDN Q931 signalling is backhauled to CCM. The only gateways that support CCM MGCP are 6608, 2600, 3600, 4224 and Cat4K/AGM. The AS5xxx support MGCP but not the CCM MGCP flavour.

Yes, CCM can be involved in the H323, in fact it has to be if the call is between IPhone and H323 GW. But even H323 GW to H323 GW can go through CCM if you point the dialpeers to CCM.

[mimckee]

The main advantage to using MGCP with callmanager versus h.323 is redundancy. With h.323 if the primary callmanager were to fail all the calls out that gateway will be dropped. With MGCP the calls will be preserved. The only platforms that support MGCP with CCM at this time are VG200, 26xx, 36xx, 6608 and dt-24+.

Thank you,

-Mckee

[oconnost]

Any chance that CallManager failover will be supported in a H.323 environment ?

Thanks,

Steve

[robrhodes]

With h.323 your failover is accomplished with dial-peer preferences.

[oconnost]

Thank you for your response. Please allow me to get this straight. Are you saying that with Dial Peer preferences, I design a dial peer pointing to each

CallManager ?

If not could you please explain.. Also, can I deploy both MGCP and H.323 within the multi-site distributed processing model ??

Thank you for your consideration..

[mimckee]

This is only failover for any new calls. All existing calls will be dropped if you are using h.323. I don't know of any way they can support call preservation with h.323. With mgcp the layer 2 is terminated at the gateway and when it registers with the new active callmanager he tells the ccm he has calls on certain b-channels. There is not really a way to do this in h.323.

Thank you,

-Mckee

[kalbasha0]

Can you explain?

Q is this a correct statement

The main reason I would use MGCP over h.323 is for failover.  If you are using a h.323 gateway and your primary callmanager goes down the calls will be dropped.  With mgcp the gateway calls will be failed over to the secondary callmanager and the calls will stay up.

According to H.323 gateway confg

There is 2 VOIP statements apply with a

Session target ipv4: Primary Call manager IP address

And Subscriber IP address