Posted by: peter

Over the last few months I have been trying to improve the management of our collection of Polycom Soundpoint IP telephones. They were initially configured by some friendly consultants with static IPs and no registration to our SIP proxy which meant that the media servers were configured to route to the IPs of phones instead of the extension. (I KNOW, what on earth were they thinking?) The stupidity of this configuration became even more indefensible when it became clear that the same company had sold us both the SIP proxy, and a TFTP based telephone provisioning server!

There seems to be a fair bit of confusion and misinformation on the net about how to:

  • Tell a Polycom phone to use a dedicated Voice VLAN that is separate from an untagged PC VLAN completely automatically
  • Tell a Polycom phone to provision it’s (SIP) configuration data from TFTP (or HTTP) completely automatically

The good news is that both of these are trivially done with simple modifications to your DHCP server’s configuration.

I am going to assume that you have an ethernet network with VLAN ID 2 used for PC data and VLAN ID 3 used for VoIP (Quite likely you are reserving VLAN ID 1 for management, but it’s not important here)

To get a phone to pass through the “PCVLAN to it’s second ethernet port while it itself uses a separate “Voice” VLAN, you need to do the following:

  • Configure the ethernet switch port connected to the Polycom phone as a “hybrid” trunk with VLAN ID 2 untagged and VLAN ID 3 tagged
  • Configure the DHCP server running on VLAN 2 to serve DHCP option 128 as a “String” with the contents “VLAN-A=3;”
  • (Re)boot the phone… (If you have already been manually configuring things you may want to do a factory reset of the phone to make sure you haven’t broken something)
  • At this point the phone should boot, receive an IP on VLAN 2, see that there is DHCP option 128 telling it to use VLAN 3, switch automatically to VLAN 3, and send out another DHCP request on that VLAN (You of course need to have a DHCP server setup on VLAN 3 also or the phone will fail here…)

This has solved our VLAN configuration option, but what about the rest of the SIP config? For that we need to tell the phone where to find our TFTP provisioning server:

  • Configure the DHCP server on VLAN 3 (The Voice VLAN) to serve option 66 as a “string” with the contents “tftp://my.tftp.server.address/” (Set this to the IP or DNS of your TFTP server)

The setup, placement and contents of the Polycom configuration files on the TFTP server are left as an exercise for the reader as there are plenty of examples of how to do that.

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Posted by: peter

Kurt Grandis carried out an awesome Django vs .NET experiment at his company:

Almost two years ago I was in a rather unlikely situation in that I was running a software engineering department containing both a C# team and a Python team…It slowly dawned on me that I had a perfect test bed. Here we had two teams using different technology stacks within the same department…they shared the same development processes, project management tools, quality control measures, defect management processes. Everything was the same between these groups except for the technologies. Perfect! So like any good manager I turned my teams into unwitting guinea pigs.
With the result:
We found the average productivity of a single Django developer to be equivalent to the output generated by two C# ASP.NET developers. Given equal-sized teams, Django allowed our developers to be twice as productive as our ASP.NET team.
Posted by: peter
While the SVN Book talks about custom logging for SVN with Apache, the example format doesn’t include one of the most important pieces of information, the SVN repository being accessed! It took me quite a while to find this, so here it is. On SUSE Linux, add the following lines to mod_log_config.conf:

LogFormat "%{%Y-%m-%d %T}t %u@%h %>s repo:%{SVN-REPOS-NAME}e %{SVN-ACTION}e (%B Bytes in %T Sec)" svn

And the following line to default-server.conf:
CustomLog "/var/log/apache2/subversion_log" svn env=SVN-ACTION
Instead of the normal unreadable rubbish, this should emit lines similar to the following to /var/log/apache2/subversion_log:
2010-04-09 14:41:50 peternixon@ 200 repo:myproject checkout-or-export 
/ r5317 depth=infinity (875377105 Bytes in 217 Sec)
Posted by: peter

Today I started to rewrite my website in HTML5 to see what it was like, and was so exited by the result that I put the new HTML5 version of the site live after only a few hours!

If you are trying to view (possibly unsuccessfully) this site with an older web browser (or any version of Internet Explorer), please upgrade to the latest version of Google Chrome, Mozilla Firefox or Apple Safari

For any web developers who haven’t yet looked at HTML 5 and CSS 3, do so soon, because it makes a lot of things easier, better, cleaner and brighter! Did I mention easier? Better?

Posted by: peter

On Friday the Sydney Morning Herald reported that an Internet censorship protest site had been set up under the banner ‘Stephen Conroy: Minister for Fascism‘ and was ironically registered under the very name of the Australian Communications Minister responsible for trying to mandate the compulsory filtering scheme in federal law, stephenconroy.com.au. Within hours of the story being published, auDA, the Australian Domain Name Authority, had shut down the site, giving the owners only 3 hours to respond to a request to justify their eligibility for the domain. Normally auDA would allow several days to weeks for this process. An appeal to request an extension was denied, with no reason given. The site was quickly moved to a US domain, stephen-conroy.com in order to stay active while the dispute with auDA is resolved.

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Posted by: peter

Petr Horava, a physicist at the University of California in Berkeley, has a new theory about gravity and spacetime. At high energies, it actually snips any ties between space and time, yet at low energies devolves to equivalence with the theory of General Relativity, which binds them together. The theory is gaining popularity with physicists because it fits some observations better than Einstein’s or Newton’s solutions. It better predicts the movement of the planets (in an idealized case) and has a potential to create the illusion of dark matter. Another physicist calculated that under Horava Gravity, our universe would experience not a Big Bang but a Big Bounce — and the new theory reproduces the ripples from such an event in a way that matches measurements of the cosmic microwave background.