Unfortunately the 2245 doesn’t ship with the correct QoS configuration and instead must be manually configured in order to attain the proper DiffServ/QoS markings between the wireless telephones (WT), the 2245 and the call server.

From the main menu of the 2245 select SVP-II Configuration, then select QoS Configuration and modify the options as depicted below;

                               QoS Configuration
                Hostname: [slnk-011111], Address: 10.1.1.10

        Traffic Class DSCP Tag
     ---------------- ----------
       Administration Default
         WT (In call) 46
         WT (Standby) 40
                  RTP 46
                  PBX 40
           Inter-SVP2 Default

Cheers!

It was a challenge to understand all the different heartbeats, timeouts and protocols that were in play between the handset and the Nortel 2245 wireless gateway and ultimately the Nortel Succession Signaling Server. With any Nortel IP phone running a UNIStim protocol there is a watchdog timer on the phone that counts down from 200 seconds. The watchdog timer must be reset by a watchdog reset (heartbeat) message that gets sent out from the Nortel Succession Signaling Server. This watchdog reset gets sent every 30 seconds. If a handset, remember now any Nortel IP handset that is running a UNIStim protocol such as the i2002, i2004, 1120e, 1140e, 1150e, 2210, 2211, 6120 and 6140 misses too many of these heartbeats the phone will reset itself usually displaying the message “watchdog timeout” indicating that the watchdog timer has reached zero and the phone is attempting to recover from the problem by resetting itself. With the Nortel 2210, 2211, 6120 and 6140 you also have the SVP heartbeats and timeouts to worry about.

If you have some IP phones that are generating “watchdog timeout” message your probably loosing packets somewhere in your network. With that said I would advise anyone with such a problem to immediately contact their voice reseller and make sure their Succession Call Server and Signaling Server have the latest and greatest DEP (patches) list. Once that’s complete you’ll need to go about the task of isolating the possible locations where you could be dropping packets. If it’s a wired IP phone then the problem is much easier to troubleshoot and isolate. If it’s a wireless phone then you’ll have a few extra steps. You’ll obviously need to make sure that you have QoS (DiffServ) up and working within your environment and you’ll need to make sure that you have SVP support enabled on your wireless infrastructure. SpectraLink (recently acquired by Polycom) actually has a library of documents to help customers configure their wireless infrastructure properly to support the SpectraLink handsets.

Cheers!

Correction: August 19, 2008
The watch dog interval is actually 200 seconds long and not 120 seconds as originally posted.

Update: August 24, 2008
It would seem that this article has generated a lot of interest including several inquiries by Nortel. So I thought I would try to add some additional explanation to help more clearly describe the problems and experiences I’ve had the Nortel 2211 and 2210 wireless handsets. I won’t rewrite the original because I don’t think there is anything wrong with it, other than perhaps missing some attention to the specific details.

The Motorola WS5100 v3.x and RFS7000 v1.1 was technically broken for anyone using the Nortel 2211/2210/6120/6140 wireless handsets. The phones would often reset while idle, because of a buffering issue on the Motorola AP300 access port. These problems have been resolved (as far as my testing indicates) in the Motorola WS5100 v3.2 and RFS7000 v1.2 software release. Through our troubleshooting of this problem we learned a great deal about the Spectralink Voice Priority protocol and the UNIStim protocol. In short the Nortel wireless handsets will go into PSP (Power Save Polling) for approximately 1.5 seconds, during that time the wireless handset turns off it’s radio to help save power and preserve the battery life. The problem occurs while the phone is idle because of the PSP mode, this is why no problems are ever reported while the phone is off-hook and actively being used. While the wireless handset is in PSP mode the wireless network is responsible for buffering any packets that are sent to the handset. The SVP protocol and UNIStim protocol can generate a lot of packets causing the wireless network to discard some packets while the phone is in PSP mode. These discarded packets can, depending entirely on the timing, cause the phone to either reset or the phone to be unregistered from the Succession Signaling server.

I’ve been asked by quite a few people what can be done to help alleviate any potential issues?

• The wireless infrastructure should be configured to support the SVP protocol
• QoS (DiffServ) should be set to “Trusted” on every Ethernet switch port that will be used to connect the different equipment (Succession Signaling Server, Succession Voice Gateway Media Card, 2245, wireless infrastructure)
• Design the wireless infrastructure so there is at least -60 dB of signal available and no more than 7 wireless handsets connected to a single access point/access port.

With all that said Nortel has literally just released v97.072 software for the Nortel 2211/2210 wireless handsets. While the release notes don’t seem to indicate any changes that are specific to “watchdog” issues it might be worth giving it a shot.

Cheers!

Update: Friday September 12, 2008
I’ve placed a copy of the Nortel document WLAN IP Telephony Installation and Commissioning (v3.3) on my website. This document should be a great help to many folks that are having issues with Nortel 22×0 and 61×0 wireless handsets.

You’ll need a Nortel Succession Call Server (along with a Succession Signaling Server and Voice Gateway Media Card) configured for “IP Line” before you’ll be able to deploy any wireless phones. If you already have any of the Internet Telephones deployed then you have already have “IP Line”. Once you have your Call Server connected to the network you just need to deploy the Nortel WLAN IP Telephony Manager 2245 (Wireless Gateway). The 2245 wireless gateway converts the Spectralink Voice Priority (SVP) used by the phones to UNIStim/H.323 used by the backend Succession equipment. Of course you’ll need a wireless network(802.11b) in place to carry the traffic. We use Motorola’s WS5000 and WS5100 Wireless LAN Switches. We’re also in the process of evaluating the RFS7000 from Motorola.

Note: we’ve currently identified an issue with the WS5100 v3.x that causes the Nortel Wireless phones to randomly watchdog and reboot themselves. We’ve also identified this same problem on the RFS7000 v1.x. We are currently only providing VoWLAN services on Motorola Wireless LAN switches running v2.1.3 software. Motorola and Nortel are aware of the issue and are working towards a solution.

The Nortel 2245 wireless gateway will literally proxy all communications between the phones at the Succession backend equipment. This requires that the 2245 assign a proxy/secondary IP address for every wireless phone (this is done in the configuration of the 2245). From the wireless network standpoint the wireless phones will have an IP address issued by the DHCP server, but the 2245 will replace that IP address with a second IP address it will use to communicate with the backend Succession environment. This is so when the Succession backend tries to signal the phone it will send the traffic back to the 2245 wireless gateway which will then transcode the signal/data and send it the actual IP address of the wireless phone. The Nortel 2245 wireless gateway also works to provide QoS for the wireless voice traffic.

Nortel has just recently release the 6120 and 6140 Wireless Phones which support 802.11a/b/g wireless networks. I’ll be evaluating those in the coming months to see how they fair against the current products.

Technical Stuff
The Nortel 2210/2211 Wireless Phones can be configured in DHCP with the vendor class of “Nortel-221x-A”. They will accept the same DHCP option code of “128” with the same format as the i2002/i2004/1120e/1140e/1150e Internet Telephone. You’ll also need to pass DHCP option 151 (IP address of the 2245 server). Software upgrades are performed over TFTP using DHCP option 66 (IP address of TFTP server).

Hopefully that’s enough to give you the basics.

Cheers!