Anyone who has ever administered a Cisco Unified Communications Manager (AKA Call Manager, or CM) system learns very quickly that there are approximately 17 billion different configuration settings in CM. All of those configuration dials have to be maintained in the right ways to get the system to do what you want.

I've taken several Cisco training courses on CM, and I felt like the thing that was missing was a real-world case study of how you setup all the pieces to interact with each other and why. There was no real "best practices" in the classes, just a lot of "this setting does X or Y" without any explanation of why you would choose to do X vs Y.

Read on for exactly that information from documentation I've been working on for the CM environment at my job.

OK, not related to work, but worthy of a blog entry at least.

The other day I dove into VOIP for the first time. I admit, I'm a bit of a holdout with regards to my home phone service. I'm also old enough to recall the days when the phone in our house plugged into the wall with that huge 4-prong plug, and Ma Bell engineer(s) needed to do ANYTHING with regards to phone jacks or phones. If you so much as clipped a wire, out came the Bell-Police :-) Getting to the point of cutting my AT&T service is emotionally difficult. I've ALWAYS had AT&T.

Anyway, I finally decided to switch to VoIP and cut my land line. I'm not there yet, as I'm currently testing out the device first. I opted for an "ooma", which is essentially a product that's "VoIP in a box". You pay for the unit (about $200 US), and that's it. Everything else is free for as long as you own the unit. No monthly charges, no fees, no regulatory charges, nothing. Free local calls, free long distance. And they support porting your land-line number to the device when you're ready ($40 fee).

A while back I wrote about using Apache as a dynamic reverse proxy. Anyone who has done even minimal research into web servers knows that Apache is the swiss army knife. It trys to be everything for everyone, and like a swiss army knife may not be as good as a more refined too at least as far as efficiency is concerned.Read the full article Transparent dynamic reverse proxy with nginx at -->

Last month's Atlanta Linux Enthusiasts' presenter, Michael H. Warfield, has posted the slides from his talk "The Brave New World of IPv6."

http://www.wittsend.com/mhw/2009/IPv6-BNW-ALE-2009.odp
http://www.wittsend.com/mhw/2009/IPv6-BNW-ALE-2009.ppt
http://www.wittsend.com/mhw/2009/IPv6-BNW-ALE-2009.pdf

Tonight's topics (7:30pm, Emory University) are:

"A Demo of the Opensuse Build Service (OBS)"

Tomorrow's Atlanta Linux Enthusiasts presentation will be "The Brave New World of IPv6" presented by Michael Warfield.

Someone on the sage-members mailing list asked about checking SSL expiration dates. We use the following script to check them via nagios (actually, we use a slightly older version that takes hostname and port instead of URL, but this is the next version we plan to roll out). I thought I'd post it here (with the permission of the author, who is no longer at Tufts) for others to use:

#!/usr/local/bin/perl
###########################################################################
#####                                                                     #
#####     check_cert.pl -- check  HTTPS,  IMAPS,  LDAPS or SMTP (with     #