I have 2 different locations, the Main Office (M) with
about 11 extensions and another office in a different location
(X) about 20 km away with 9 extensions.

i would like to combine the IP PBX in both locations to form one network.
Question
  1. which is the best device to use  eg cisco?
  2. what is the best software to use.?
  3. is there an android app that can act as a client app and sales agents can use it to connect to the PBX? 

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Best Regards
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Isaac Kimotho Kanyanja
Software Engineer
P.O. Box 75380, 00200 - Nairobi
Cell: +254 724 346 453
Skype:  kimotholefty