Traffic Shapeing on Nortel's router

[Brat]

Hi, all

How to implement traffic shapeing on Nortel's routers? I have found informations about DiffServ and Protocol Prioritization, but I haven't found any informations about traffic shapeing.

Thanks,
Brat

 

[Jynxx]

That depends...are the Nortel routers in question, connected to Frame Relay or PPP links? If so, you can NOT do traffic shaping or QoS.

Protocol priority HAS to be on for the WAN port if connected to Frame or PPP. The reason is that there is a hidden queue that the LMI messages reside in that is above the high queue. Nortel routers can only handle one de-queueing algorithm at a time. Protocol priority is one... DSQMS is another. If DSQMS is turned on, it automatically disabled protocol priority and the router will quickly lose control of the line and the link will start bouncing.

Don't even ask me how I know... ;-)

If you need to do QoS, you will need a different manufacturer of router. Cisco is recommended. We just swapped out 55 Nortel routers with Cisco just because of this. Sickening, but nothing that you can do.

According to Nortel, they plan on potentially addressing this in 17.x I believe. We'll see...

 

[Brat]

Hi, Jynxx

Thanks for informations, it is really god to know about hidden LMI queue. I really like Nortel's equipment, especially secondhand is quite cheap copmared to Cisco hardware. In this situation I will prepare linux QoS with CBQ,RED,HTB or other algoritms to perfor traffic shapeing, using transparent bridge filtration method, and of coures I will wait for 16.x and 17.x software releases.

Thanks again,
Brat