I thought I would take some time to shamelessly plug a product that I recently purchased for my organization.
We are currently working through an issue that is affecting our Nortel 2211 Wireless telephones on our Motorola RFS7000 Wireless LAN Switch. In short it appears that the phone is resetting itself for unknown reasons. The problem is very intermittent and sporadic, hence it’s very difficult to recreate. The vendors involved in the problem, Motorola, Nortel and Polycom (Spectralink) are all asking for wireless traces of the problem. In order to capture the problem we need four laptops; three laptops tracing on each of the wireless channels in the 802.11b 2.4Ghz spectrum and one laptop tracing on the LAN side of the RFS7000. Needless to say that is a lot of hardware to setup. And the wireless laptops really need to physically move with the wireless telephone as it moves through the building (wireless network).
Then I heard that CACE Technologies had a hardware solution that worked with WireShark and allowed for simultaneous packet capture on all three 802.11b channels. Using three AirPcapEx USB adapters I could use a single laptop to capture all three 802.11b channels saving me a lot of hardware and a lot of time trying to assemble/merge the different packet traces.
I’ve been using the solution for the past week and it seem to work well. It was perfect timing because WireShark v1.0 was released earlier this week. Even though it’s a single laptop it can still be a bit of a logistical pain with the three USB adapters and the three antennas. I got some really interesting stares walking around the building with this octopus looking thing on top of the laptop keyboard.
Packet analyzer says
I’ve also used AirPcap quite extensively to debug embedded systems WiFi communication.
You might wanna try to feed the pcap files to NetworkMiner (from sourceforge) in order to get a good overview of the sniffed traffic.
Michael McNamara says
Thanks for the post!
I’ve come across NetworkMiner in the past but never had the opportunity to really dig into it.
I’m currently searching for an application that will compare two traces of the same packets taken at different points in the network. I might have to roll up my sleeves and write some code myself.
Michael Happe says
I found out usefull info in your blog.
It seams that you have the same type of problem we have with our 2211 phone
these phones reboot from time to time (some 5 time in a day)
Some spectralink 2211 left in a charger loses shut down while being charged up.
freeze of the phones
When wireless is weeker the call is completely droped instead of losing quality
all these problems are extremely anoying and we start to replace Spectralink with mobile as communication is critical to our operation.
this is a sad turn we need to take but my believes that spectralink/norlel are bad solution for us
when speaking to global nortel account manager, i asked the question:
why are Cisco wireless IP phone keep conversation in degraded mode when por wireles signal, and why spectralink 2211 phones stop the calls
“his answer is , spectralink protocol is made as if the wireless network was a cable network. Cisco does work like that”
Michael McNamara says
I’m sorry to hear that your having issues. In my experience the problems with the SpectraLink handsets can usually be traced back to the network. In my case we had a specific problem with the Motorola v3.x software that was running on the WS5100 Wireless LAN switch. In the end we discovered that Motorola had inadvertently reduced the amount of buffering on the 802.11a/b/g Access Port (AP300). Once they corrected the buffering the problem was resolved.
You may wish to also look at another article;
Edit: you didn’t mention if you have QoS/SVP support enabled on your wireless solution. You’ll most certainly need QoS/SVP support enabled and configured properly in order to use the phones.