Dimensioning an Asterisk system

Typical questions asked on the mailing asterisk-users are:




The only rule of thumb we appear to be able to provide is this: Asterisk 1.2 start to run into problems around 220 concurrent SIP calls. Asterisk 1.4 scales much better and can handle nearly double the call setups/second as well as total concurrent traffic. Moreover, Early testing of Asterisk 1.6 using hash tables shows a SIP performance increase compared to 1.4 of factor 3 to 4. In asterisk 10 the performance increase in sip udp handling is around 2 to 3 times faster compared to Asterisk 1.8.

Apart from this unfortunately there are no simple answers. You'll need work through the following checklist to at least get nearer to an answer or be able to post a meaningful question to asterisk-users.

1. What type of phones do you plan to use (analog, SIP, Skinny, H.323, MGCP)?
2. How many phones will you operate?
3. How many external lines do you have, and of which type (analog, BRI, PRI, T1, VoIP)?
4. How many concurrent internal/external calls do you expect (example: 30%)? Consult the Erlang tables (see links below) if in doubt. ...