I'm running a 28 user office with Asterisk 1.4.17 on a Dell R200 server using a Sangoma A101D and things are working nicely.
Does it make sense to setup a second Asterisk server as a virtual machine (we have VmWare ESX running a lot of different systems here) and move all of the local SIP devices, voice mail, conferences, etc over to that machine, leaving the Sangoma on a dedicated box? I'm thinking of the future where we may add another 25 to 35 internal staff and I would setup another virtual server for the new users, allowing me to limit the load on each virtual machine, plus allow a way to do upgrades that only affect a small number of my users.
I know that multiple Asterisk servers is common, but it seems that these are typically a new box with it's own PSTN hardware when the user load his a specific point. I'm interested to know whether people see any advantage (or disadvantage) from separating the interfaces from the systems handling the user load and handsets?