8600 & SMLT interfacing to other non Nortel switches via SMLT

[VOIPaintEASY]

What recommendations or examples of actual implementations would you recommend to interface non Nortel closet switches to 8600's using SMLT with dual uplinks? Would you recommend SMLT on the 8600's and LACP on the layer II edge switch device? I am exploring non Nortel edge closet switch options and would like some input of interfacing using SMLT on the 8600 side and at least 2 uplinks for redundancy to the closet edge switch.

 

[anthonyanderberg]

Once while doing evals I hooked Cisco 6500 and 3750 modules to a pair of Nortel 8600s running IST/SMLT for fun. I configured the Cisco ports as Etherchannel and the 8600 IST pair ports as SMLT... everything seemed to work fine, although have never had to put a similar mixed vendor solution in production.

 

[VOIPaintEASY]

correct, I too have ran Cisco using Ethercahnnel peering to SMLT and it works perfect. Was wondering about 802.3ad (LACP) as most servers, etc. want to use that protocol.

 

[WillyHe]

Cisco Etherchannel or any other way to do link aggregation should seamlessly cooperate with Nortels SMLT.

The 8600 supports 802.3ad (LACP) but I'm wondering what the LACP scaling numbers are for the 8600.

 

[VOIPaintEASY]

As an FYI. We have ran tests and found 802.3ad to work. We did find the failover (uplink failure) not to be as seemless as SMLT to SMLT or MLT though. It does work but always seemed like 1 link failure would be near hitless and the other would take 5-10 ping timeoputs before taking over. We are going to go with the new Nortel 4500's that just came out in the nick of time. Was feeling like we had no choice but to go a diff. route until these came out.

 

[WillyHe]

Depending on the "protocol"(*) used to connect switches the SMLT time-out can vary a lot.

(*)
- Auto negotiate and NO auto negotiate will give the fastest SMLT fail-over times.
- SFFD (Nortel proprietary "Single Fiber Fault Detection protocol") gives SMLT time-outs of > 20 seconds.
- No experience with LACP.

The SMLT time-out depends on the time it takes for the connection "protocol" to "know" a link is down ==> sub seconds SMLT will know.
This is also true for MLT and DMLT.