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New Member

MGCP & H.323 SRST ... ?

I undertstood from Mr. Graham (of Cisco) that the MGCP fallback feature will come about in the soon-2-b-released 12.2.11T IOS , whereby it allows

an MGCP Gateway to become H.323 when the CallManager is unavailable, which in turn allows SRST to utilize the gateway.

I have the following query i hope to be enilghten on :

1. SRST is invoked when the WAN link goes down, and the GW is thus unable to get a respond from the CCM. Hence, all IP Phone would fallback to the SRST gateway as a tentative "CM". MGCP supports redundancy when

the primary CCM goes down, the standby/backup CCM will be used instead.

As MGCP will be incorporated in2 the latest IOS, in the scenario whereby the

primary CCM goes down (& NOT the WAN link), should'nt it fallback onto the standby/backup CCM instead, rather than allowing the H.323 SRST to be invoked & taking over the role ?

So when will SRST be invoked then ? only when there are neither responses from the primary & backup CCMs, &/or when the WAN link is down..?

thank Q!


New Member

Re: MGCP & H.323 SRST ... ?


IP phones won't fallback to the SRST router until none of the CMs are reachable. That's why SRST router's ip address is shown as the default gateway. MGCP Gateway fallback can coexist with SRST.



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