[lug] What would you like to know about Asterisk?

[Nate Duehr]

Sean Reifschneider wrote:
 > Next month I'm going to be talking at BLUG about Asterisk.  In order
 > to tune the talk to the audience, I'd like to hear what kinds of
 > things list members would like to hear about.

Quite a challenging topic, Sean.  Asterisk is the 800 lb gorilla in the 
open-source telco world.  Lots of products based off of it, etc.  Very 
cool stuff, but hard to do a short talk on!

I work on stuff like Asterisk for a living, so I could ask evil 
questions that are so far above everyone's head that's just learning it, 
that I won't bother!  (GRIN)

Looking over your slides, I would point out that Asterisk has been 
around long enough, nowadays it's becoming used for more than just "PBX" 
services.  An example would be 2-way radio linking...

http://app-rpt.qrvc.com/

It's almost to the point where a talk on Asterisk is more of a "What 
WON'T it do?" in the telco/VoIP world now, instead of a "What are all 
its features".  Like Apache for web services, the Asterisk core has 
become the VoIP telephony swiss army knife.

That said:  There are applications it does NOT do well.  For example, it 
does conference bridging, but not to professional quality standards. 
The latency it introduces into the audio stream doesn't meet any 
carrier's specifications for quality.  (Most carriers want audio energy 
transported back to the receiving handset in something around 100mS or 
less, if they can get it... and all receivers must receive within less 
than 20mS of each other.)

People's voices come out of different phones at different "times", and 
even though for MOST applications that's not a big problem... say on a 
big trading floor with 25 phones in the conference, listening to the 
room "echo" like that whenever someone speaks, is REALLY annoying.

Adding CPU to it ALWAYS helps when you're doing highly CPU-intensive 
stuff but it simply can't do with a generic CPU, what a custom ASIC or 
DSP chipped hardware platform can do.  Muti-core might help (I've never 
looked at their conferencing code), but not sure if that code is threaded.

For your presentation -- you might want to look at the "easy" ways to 
get started... some of the LiveCD distros that have it pre-loaded and 
ready to go, complete with web interfaces, etc...  if you have the right 
hardware or ATA's, etc.  That's a great way to help someone get started 
with it.

Sadly, I still haven't built one of these for home.  Staring at SIP 
traces at work all day long in Wireshark will "cure" anyone who wants to 
"play with phone systems" for a living.  LOL!

Nate