When attempting to use su, you may receive the following error:

# su - otheruser
su: cannot set user id: Resource temporarily unavailable

This is caused by the PAM limits.conf file. Often (always?) it's because the target user has exceeded the max number of processes allowed. You can verify this with ps.

# ps -eLF |grep otheruser |wc -l
1127

In this case, 1127 is greater than the max allowed of 1024. To fix this, set the nproc limit higher, or stop any unwanted processes.

Thanks to everybody who attended my OpenWest presentation today. Here are the configs I used in the demo. Happy encrypting!

When adding a new DUNDi peer in Asterisk, after updating dundi.conf and using astgenkey to create the RSA public/private key pair, Asterisk will emit the following error:

pbx_dundi.c:1331 update_key: No such key 'foo' for creating RSA encrypted shared key for '00:01:02:03:04:05'!

I will be at the 2014 OpenWest conference with a presentation titled "Secure Your VoIP with Asterisk and Kamailio". Looks like they have me penciled in for 3pm on May 9th. Watch the schedule for changes and take a look at all the other awesome talks as well. I've attended and presented a number of times at OpenWest (aka UTOSC) and it's always a great venue.

On a fresh install of Fedora, I tried installing Jitsi but was getting a horrible error. Didn't matter which SIP account I used or how I had my audio set up, I consistently got this error: