CMS Edge & Cisco Expressway
• CB selects the TURN for the clients
• CB randomly selects max 3 TURN servers and sends the details to the client
• Client forms a TURN binding with all 3 TURN but sends media thru only one
• All TURN servers must be of same capacity for CB/CBG it is associated with
• CB doesn’t know TURN capacities, so admin must do the capacity planning well
• With no XMPP service, session stickiness is not needed anymore. So LB might not be needed
How CMS Software Works
• CMS not designed to give hardware or process level isolation based on the interface
• CMS is not designed to connect to different networks of trust levels (e.g., DMZ & Intranet)
• CMS software is not designed to handle attacks which spans between interfaces
• Once CMS software gets compromised, access to all interfaces CMS is connected to is available
Some Points to Remember
• CMS Edge is not Expressway with Inside and Outside Interfaces
• CMS Edge must connect to only 1 network (DMZ)
• Updating CMS routing table just enables routing to two networks, it doesn’t give the process level isolation expected from a DMZ device
• CMS Edge does not work the same way Expressway works in a DUAL NIC deployment
