Ekiga on the intranet

Written in the mid-afternoon in English • Tags: ,

Ekiga has a problem talking from behind a firewall, or maybe the problem is that both the firewall and Ekiga are trying to be too clever. I’m running siproxd on the firewall to transparently handle SIP connections. All the hardware phones and ATAs as well as X-Lite work well, but Ekiga fails to register.

The fix is controversial: I’m disabling STUN.

gconftool-2 -s /apps/ekiga/general/nat/stun_server --type=string

However, this means Ekiga won’t work from less “intelligent” networks anymore. Since I’m considering Ekiga for my laptop, this might be a problem. Maybe I should try X-Lite under Wine.

Ubuntu doesn’t like AMD?

Written late in the morning in English • Tags: , ,

I’ve been observing a really strange problem on Ubuntu Server 8.04: processes are sitting in limbo not doing anything. I first observed this as phones losing their SIP registrations periodically (but at random intervals).

When debugging the issue, I saw that a ping running on the system would often just sit there, not sending more packets, sometimes for seconds on end (I didn’t always wait to see if it would ever continue). Since hitting a key on the keyboard would immediately be echoed back, it wasn’t a problem with the terminal or ssh connection. Pinging the system from another would work without problems. Interrupting ping would report no packet loss (which was true — you can’t lose replies to packets you didn’t send).

My best guess is that the alternative scheduler chosen by the Ubuntu developers for the server kernels doesn’t work as intended on AMD CPUs (or just the Athlon XP, or some other part of the hardware I’m using).

My “fix” was to switch to Debian 5.0 (lenny), which doesn’t exhibit this problem at all.

I could have tried with the desktop edition of Ubuntu, but can’t really spare the time right now. Especially since I now have something that works reliably again.

I did try with different network hardware, though. I was originally using an SMC card based on ns83820 (but for some reason not reporting anything at all with ethtool — works fine with the gsip driver on NetBSD). I then switched to a Netwjork “brand” card based on r8169 (well liked by ethtool). No difference, but stayed with the latter (working ethtool is always nice).

Two power outages this morning (or more — I was out). The results: one dead Kaveman and one dead power supply on a switch (external, thankfully). Which in turn resulted in some hunting of rogue DHCP leases from an OpenWRT AP…
Being on the road is a challenge to my music listening habits: no Squeezebox and no Spotify. I’ve managed ok with my iPods and Last.fm streaming. However, there’s been no good reason to miss Spotify, though, even when running Ubuntu on the laptop. Just follow the instructions to install and run Spotify under Wine.
“Suddenly” Firefox had begun to pin the CPU at 100% even when not doing anything. I started to uninstall related recently added software. Looks like the culprit was swfdec-mozilla, which I had added hoping to get Cooliris working (no such luck — didn’t work with flashplugin-installer either). No flash now, but also no load when browsing the web. (And no burning sensation from the laptop.) (1)

Asterisk installation

Written late in the afternoon in English • Tags: , , , ,

Just a short note on getting a minimal Asterisk environment installed on current versions of Debian and Ubuntu:

aptitude install asterisk
m-a a-i zaptel
modprobe ztdummy

Also add ztdummy to /etc/modules so it gets loaded when the system starts.

If the m-a command is not found, install the module-assistant package.

New installations of Debian have rsyslog as the system logging daemon. Upgraders, however, will be left with sysklogd — and no instructions on how to switch. I’m hoping purging the old one and adding the new one will work ok, as I’ve made no local mods to the logging configuration…

Upgrading to lenny

Written in the mid-morning in English • Tags: , , , ,

I’ve been always a fan of the robust upgrade procedure documented in the Debian release notes, which has worked without problems even over ssh to remote machines. This has made upgrading very painless (at least since sarge — I haven’t used Debian actively longer than that).

Yesterday I ran into a problem, though, which was only saved by having remote console access. I have a system with a slightly more complicated disk setup: it has two SCSI disks running as a RAID 1 array using md and lvm. Upon rebooting after the upgrade, the system didn’t reappear on the network. What I found on the console was the initramfs panic shell: the root file system had not been found. Rebooting the old etch kernel worked fine.

The workaround proved to be very simple, once I distilled it from the search engine results. Just add rootdelay=10 to the kernel options in the bootloader. I’m using GRUB so this translates to editing the kopt line in /boot/grub/menu.lst and running update-grub.

I had also added raid1 to modules in /etc/initramfs-tools and regenerated the initrd, but that (alone) didn’t help. I’m not even sure it is needed at all — it might already be included anyway when using MODULES=most in initramfs.conf.

Images, please

Written at lunch time in English • Tags: , ,

I’m following most web sites with Google Reader these days. With some sites I’ve noticed that images don’t show up in the reader interface. I figured this would be because the site is attempting to protect against hot-linking to its resources — and it seems I was right.

The quick fix with Firefox is to disable sending referer-information for inlined images. You can do this in about:config by changing the value of network.http.sendRefererHeader to 1.

While there, I also changed network.http.sendSecureXSiteReferrer to false. This prevents referer-information from being sent between different secure sites.