NIC Port Speeds

[Seagull]

Please help, as this is driving me mad!

We currently have both Polycom VSX 7000 and 8000 units connected to a switched network comprising Nortel 5520 switches. What is the recommended port and suplex settings for both the switch and VSX units to obtain the best video quality..........

If anyone knows, this will save a heap of time on testing!

Cheers

[senthil]

vsx series will support 100mbps so you can configure both to 100mbps with full duplex for better video quality.

senthil.

[Kevin]

vsx series will support 100mbps so you can configure both to 100mbps with full duplex for better video quality.

senthil.

Be VERY careful!

You must make sure that the network switch ports and the equipment ports are set to the same thing - otherwise you will get a duplex mismatch.

If one side is set to Auto the other MUST be set to Auto. If one side is hardwired (for example to 100/full) then the otherside MUST be set to the the same (in this example 100/full) and NOT Auto - otherwise you will get a duplex mismatch.

Misconfigured ports is probably the number 1 cause of issues I have seen out there in the field!

Kevin

[asoussa]

Be VERY careful!

If one side is set to Auto the other MUST be set to Auto. If one side is hardwired (for example to 100/full) then the otherside MUST be set to the the same (in this example 100/full) and NOT Auto - otherwise you will get a duplex mismatch.

Kevin

I would suggest not to beleive any rule!! I t depends on the VC NIC and Ethernet switch manaufacturer; I even had VC working fine with ONLY VC set to Auto and switch set to 100 full duplex!!

Golden rule is NO RULE and you have to try all the combinations!! Most likely to work if both set to the same speed. Enjoy!

[Sean Lessman]

I even had VC working fine with ONLY VC set to Auto and switch set to 100 full duplex!!

I would not recommend this as a rule of deployment. It will cause you problems eventually.

Sean

[trapehzoid]

I would suggest not to beleive any rule!! I t depends on the VC NIC and Ethernet switch manaufacturer; I even had VC working fine with ONLY VC set to Auto and switch set to 100 full duplex!!

Golden rule is NO RULE and you have to try all the combinations!! Most likely to work if both set to the same speed. Enjoy!


No, as you describe is if you can use Auto or not. The if one side is forced, the other side must be holds true for all vendors and all models.

Always start with auto, and only go forced if you find a incompatibility.

[Slimey]

I find that most HP Procurve switches with Polycom 4000/FX/VXS work very well on auto.

[ranjithvarier]

hi,

Please refer Kevin's reply. i have faced lot of problem with different speed configuration . Please check the switch Speed Duplex mode (By deft it should be in "Auto") and proceed. i do recommend to put both in "auto" mode , it will automatically negotiate in to 1oo MB Full Duplex mode.

Regds

Ranjith Varier

[shailandra]

I can suggest for the Polycom device, if the polycom is connected to Cisco switch then quite possible is that even you have hadr coded both sides with 100Full you may find alignment errors. please refer the cisco link attached.

http://www.cisco.com/en/US/products/hw/switches/ps700/products_tech_note09186a00800a7af0.shtml

The solution to avoid duplex mismatch as per Cisco is keep codec 100Full and switch on 100half. However when I tested this config it did not work. most of the places with us Auto/Auto works well.

Polycom may not accept, but he NIC card in the codec may not be 100% IEEE 802.3u complient. Hardware incompatibility and other issues can also exist as a result of vendor-specific advanced features, such as autopolarity or cable integrity, which are not described in IEEE 802.3u for 10/100 Mbps autonegotiation. Generally, if both the NIC and the switch adhere to IEEE 802.3u autonegotiation specifications and all additional features are disabled, autonegotiation must properly negotiate speed and duplex, and no operational issues exist.

[JFCOMEngineer]

I can suggest for the Polycom device, if the polycom is connected to Cisco switch then quite possible is that even you have hadr coded both sides with 100Full you may find alignment errors. please refer the cisco link attached.

http://www.cisco.com/en/US/products/hw/switches/ps700/products_tech_note09186a00800a7af0.shtml

The solution to avoid duplex mismatch as per Cisco is keep codec 100Full and switch on 100half. However when I tested this config it did not work. most of the places with us Auto/Auto works well.

Polycom may not accept, but he NIC card in the codec may not be 100% IEEE 802.3u complient. Hardware incompatibility and other issues can also exist as a result of vendor-specific advanced features, such as autopolarity or cable integrity, which are not described in IEEE 802.3u for 10/100 Mbps autonegotiation. Generally, if both the NIC and the switch adhere to IEEE 802.3u autonegotiation specifications and all additional features are disabled, autonegotiation must properly negotiate speed and duplex, and no operational issues exist.


I don't think that what you quoted means to set the switch to half and the codec to full. The article is refering to the switches continual monitoring of the duplex state, and the fact that a NIC that is not compliant with 802.3u that is set to auto may renegotiate it's duplex setting on the fly, causeing intermittant problems that are difficult to diagnose. I have a 99% Cisco network, and none of my Polycom (or other equipment) is set up this way. I keep all of the polycom equipment hard coded to 100/Full, and do the same with the switches. What you described is a classic duplex mismatch and will cause problems. I was curious about your comments, and so I set it up in the lab with a 7000 VSX and a 2950 switch, and added another system (Tandberg Edge 95 in known good configuration) and saw a classis duplex mismatch.

Regards,

Wes

[genroxbro]

hi jason

well thanx for the information
this entry of the 2nd NIC was buggging me from the time i took the raq
well hope to see that the porpose it is supposed to be there for will soon be provided to us :-

Kapil
Let me introduce myself.