10mbps Full Duplex vs. 100mbps fd on VTC

[warheed]

Hi guys,

I am just curious. is there any changes in video quality if all of my vtc equipment/switch ports it use is sets to 10mbps full duplex instead of all the vtc equipment/switch ports is configured as 100 mbps full duplex? the reason why i asked is, we have been testing our recently installed vtc and mcu and the port settings was changed from 100mbps full duplex on all switches and all vtc's to 10 mbps full duplex and they were saying that it works fine on 10mbps than when it is on 100mbps. I find that strange, although one guy said that it doesnt matter whether it's 10 or 100 as long as it matches on both the vtc's and the switches since a 2mbps call can still fit in to a 10mbps which logically i believe is right, but my eyes tells otherwise, for me it always works best with the 100 mbps full duplex.

Hope that you could enlighten me on this.

Thanks a lot.

[AceVid]

One of the most common causes of performance issues on 10/100Mb Ethernet links is when one port on the link is operating at half-duplex while the other port is operating at full-duplex.

http://www.cisco.com/warp/public/473/3.html

There is a silent performance-killer out there, one so inconspicuous that it is hardly ever looked for or even suspected. You could suffer from it and never know it, as it robs a site of performance but not connectivity. This performance-killer has a name: Ethernet duplex mismatch.

If one end of a connection (device or Ethernet switch) is set for auto-negotiation, and fails to see auto-negotiation at the other end, the former sets itself to the default, half-duplex.
Auto-negotiation can sometimes fail, even when both sides are set to auto (although this isn’t as prevalent as in the past).
Some routers re-negotiate auto-speed or auto-duplex, which can introduce jitter.

If building wiring is CAT 5 or better, then set switch ports and devices to 100/full if supported on switch.

[Conquest_Tsi]

yes definately 100mb full hard coded.
10mb? dont bother.

[warheed]

I was just confused, because the settings of the switch where our vtc's are connected are set to 100mbps full duplex on all sites, so during installation and testing, we have set the lan settings of all vtc's and mcu to be 100mbps to match that of the switch settings. then one guy have changed the settings of the switch ports,mcu and vtc's to 10mbps full duplex and told me that the quality of the video has improved which i didnt agree at all. i just want a clarification on this if this can be really true that's why i asked the question.

[Conquest_Tsi]

No worries, that guy dosnt sound normal, its like saying 'a 128k call looks better then 768k'. :rambo: