ten8ous1

There are several variables to consider. How large are your main sites.

Do you have a uniform dial plan amoungst sites.
Avaya and Cisco have unique ways of handling conflicting dial plans in my opinion. Both are less than innovative in that aspect.

Are you looking ofr enterprise wide licensing and administration. If so once again they both offer it however each not without caveats.

Cisco SRST provides basic telephony in the event of a failure.
Avaya LSP's have the leg up in this aspect.

I have a ton of things I could point you to look at but without understanding your goals they are just shots in the dark.

If you want to continue the discussion just expand on your requirements.

Cheers-

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