Need clarification on a few topics

I am reading the Asterisk O’Reilly book, and as I’m reading, I have a few questions the book doesn’t really answer.

The book seems to recommend Kernel 2.6 but a lot of the examples talk about 2.4. A lot of Linux distrobutions are shipping with 2.4 right now (Slackware, and I think Debian). Is it worth upgrading to 2.6? So far, the only advantage I have seen in the text for having 2.6 is not having to load that USB daemon.

When running the /usr/sbin/safe_asterisk (I think thats the path anyway), there is an option in the config file to email (NOTIFY) when the system unexpectidly shuts down. Is it possible to email several recipients?

The book talks about 2 ways to sync the data transfer: Digiuim PCI card or the ZTDummy daemon. My guess is that it’s better to use the PCI card to sync because there is less load on the processor as a result. Is this correct? The book didn’t explicity say this so I am just clarifying.

The book descirbes a lot of features that can be enabled to utilize MMX technology. Is it advisable to buy your motherboard/processor combo for the server with MMX in mind?

When used in a corporate enviorment, is it advisable to use PSTN for outside calls (utilizing a FSO interface) or is VOIP developed enough to for use in the outside world? I have only had a VOIP conversation with somebody over a Vonage system. I don’t know what his network topology looked like, but I was not thrilled with the call quality.

Regarding the call start signals (ground/loop/kewl) are any of these compatible with eachother? The book hits that kewl and loop might be compatible, but it never outright says it. When installing a Asterisk system using existing PBX terminals, is it necessary to determine what type of start signalling they use? How is this accomplished?

Thank you.

Also, when choosing signalling methods, is the syntax:

The book has it both ways, Im assuming one is a typo.

It’s probably worth upgrading to 2.6 because sooner or later you will want to anyway and it’s reached the stage of development where it seems to be nice and stable now. However, as far as Asterisk’s concerned, it shouldn’t make any difference to the way it runs.

If you have a look through the safe_asterisk script, you’ll find your answer (indirectly)…

                        if [ "$NOTIFY" != "" ]; then
                                echo "Asterisk on $MACHINE exited on signal $EXITSIGNAL.  Might want to take a peek." | \
                                mail -s "Asterisk Died" $NOTIFY

You can see it uses ‘mail’ to send the email. So you have a look at the ‘mail’ man page and it tells you:

     mail [-iInv] [-s subject] [-c cc-addr] [-b bcc-addr] to-addr...

which means, you concatenate addresses, separated by whitespace. I.e., the following should work (at the top of that script)

NOTIFY=‘name1@domain name2@domain’


Processor load is irrelevant - it’s only timing. The card has a hardware realtime clock onboard. If that’s not available, ztdummy just gets a timing source from the kernel. It should be negligible in terms of processor load.

Whether you want to use internet telephony or the PSTN (or - maybe more useful - a combination of the two) depends on your requirements. It also depends on your ability to provide a good enough internet connection for the number of concurrent calls you are likely to need - as well as (and preferably separate from, in some way) your other internet use requirements.

The quality of internet telephony (as distinct from “VOIP” - which includes telephony over ethernet and other things) can be extremely good. But you have to have the setup right.