Todd Stowell Online

I typically don't write blog postings about issues with technology since I am constantly immersed in it, but today I feel the need to post this bit of information in the hopes that one day, some user like me will stumble upon it and find the solution they are looking for.

I have been setting up an Asterisk / FreePBX setup for my office which consists primarily of remote users. The Asterisk / FreePBX solution is provided by Aretta, which is a hosted Asterisk / SIP provider. Running FreePBX 2.3.1.1, we have been beta testing the service with both a softphone (eyeBeam/X-Lite) and dedicated phones (Grandstream GPX2000).

The configuration of the phones themselves are relatively straight forward. The issue that I will discuss today relays around BLF. BLF stands for Busy Lamp Field, or in more layman terms - it shows the status of Multi-key extension buttons on your phone. If a user is on the phone or receiving a call, it either flashes red (when ringing) or is a constant red (when the user is on the phone).

The issues that I have recently been running in to caused some substantial headaches in determining the issue. Using Google as my guide, I was able to find and configure the hard line phone to make and receive calls. However, the BLF fields were non-responsive. Secondly, I had been beta testing the softphone for about a month and was able to see extension status until it one day stopped working.

By the powers of elimination, I was able to figure out that it wasn't a service or phone issue, but simply an issue with my Netgear WPN824v2 wireless router.

Within the WAN setup, if you uncheck "Disable SPI Firewall" and restart your phone, the BLF's work. When this feature is enabled, there is no way to set a DMZ on the IP of the phone as this supersedes it.

I know this is a horrible and very short report of what was done to fix it, but at least someone somewhere might find it useful.

Labels: Aretta, Asterisk, FreePBX, Grandstream, Netgear, SIP