Multi site with centralized call manager and Cisco expressway

[kingvoice]

Hello Experts ! 

                     What will be the best design for b2b calls while having two sites with video endpoints by using expressway  core and edge ..and single cucm cluster .

[Chris Deren]

Not sure what you exactly mean here, but since the call processing is centralized in I am assuming one data center then you would place your Expressway-C and Expressway-E virtual machines in the same data center in proper networks (C in voice vlan and E in DMZs)

The Expressway deployment guide should cover all you need:

http://www.cisco.com/c/en/us/support/unified-communications/expressway-series/products-installation-and-configuration-guides-list.html

[kingvoice]

what i mean  is that one site have publisher , subscriber and expressway (E and C ) and other site

has one subscriber  . Do i ihave two use clustering between expressways or deploy expressway standalone for this site .because call routing and domains are different for both sites .

[Chris Deren]

Only if you want redundant Expressway deployment, you can cluster Exp-Cs together and Exp-Es together, however the latency between the data center needs to be below 15 ms. Keep in mind that you will not be able to control which user connects to which Exp-E as that will be decided via the DNS srv records.  If you feel like Expressway redundancy is important to you and the latency requirements are met and you have proper DMZ networks to host the EXP-Es in each data center you can absolutely do it.