asterisk intro¶
SIP = almost universal VOIP protocol IAX2 (don’t use it!) Codec used to transfer voice-to-data is ULAW
Channels = how many translations from voice-to-data you need to handle. Generally about 1 channel unless you have scaling issues.
Registration = how your box is registered to accept calls for a particular number
Asterisk can do:
- conference calls.
- caller ID
- special prompts
- voice mail
- asterisk-to-asterisk can be free because there is no middle parties
- telemarketer torture
AEL = Asterisk Extension language¶
A C-like language used to configure the behavior of an asterisk installation
Warnings!¶
- People can hack into your box and call Siberia.
- SIPVicious is a tool originally written to check for hacks against Asterisk but is used to hack.
- Can it be placed in the cloud or do we need a datacenter?
- The internet goes down
- 64k bandwidth each way
- Echos are troublesome (Open Source Echo Canceller)
- Huge amounts of servers to run this thing
Changes in install screen¶
- include the sounds in the codec (last three items)
Thoughts¶
- check asterisk hosting
Resources¶
- O’Reilly book: Asterisk: The future of telephony