bandwidth and latency

[epping]

in a WAN situation i was wondering what distance and link speeds you guys what tested over.

I did a presentation in germany yesterday using a VL10 andn my VD was back in our UK office, the link was 34 MB so quite large, anyone had any success over smaller links??

[thechicco]

I'm starting to test with 20 odd users via a 10MB MPLS cloud to our VD's in our datacentre. Not noticed any slowdown and this is with lots of DB replication, AD and Exchange traffic. Geographically however they are literally only 5 miles apart.

I plan to put 800 users on initally but we will be upgrading the circuits to redundant 100MB.

[epping]

thanks, we have a office in Dublin that we would like to replace all the desktops with VD, its a 2 MB leased line.

I did see bit of a performance degrease when i was in germany yeserday

[davlloyd]

We are running cross atlantic with latencies over 140ms with no issues. We are testing further for small offices and hoping to get tolerance around the 250ms range. Important thing is to ensure the latency is consistent so that they user experience is not jumpy.

With low end leased lines of 2MB or less the bis issue will be printing and ensuring there is no impedence of the RDp traffic with print traffic.

[MartijnLo]

We have 20Mbit running from Holland to Mumbai @ 160ms latency.

We have had complaints about screen refresh speeds but haven't had time to examine if this is printing related.

[Virtual_Desktop]

There are several low cost tools that could help you simulate latency and bandwidth such as Network Nightmare, Shunra, etc. Latency is going to be the real killer on performance as long as you don't have competing traffic on your pipe. Do you know what your average stream size is per user? Most CONUS latencies should be under 75ms and from the us to Europe should be about 150ms. Based off of the previous posts, the latency shouldnt be the killer untill you start to get higher and that will start to take the shape of slow key responce, screen refreshes etc. The bandwidth per user is what is going to start to effect performance. Add other applications to the WAN and something's gotta give. There are WAN optimization products out there that can reduce the amount of RDP traffic on the WAN and provide some nice QoS benefits as well. Drop me an email and i can tell you a bit more...

[girish_srinivas]

Hi guys,

We have setup about 400 VD, all the users connect thro MPLS network connectivity, using a Linux based thin client, we do have few challenges in performance.

• We have sufficient BW.

• The QoS and BW reservation /VD session is enabled ( 30 k). after this we see lot of improvement, but in the following it does not match a Desktop performance.

• MS Power point slides presentation.

• Opening high graphic PDF documents,

The screen loads frame by frame

We did considered Registry/Desktop perf settings recommendation given by VMWare and in some blogs, but still requires good turn around..

Please suggest any good Tweaking, Tools available to make it equivalent to DT.

Girish

[davlloyd]

If the issue is latency then typically you will see issues with both screen rendering and key stroke relay delays. If it is purely heavy graphics that are displaying issues then it could either be bandwidth or performance at the client or guest end, What type of clients are you using and what is the config or your guests?

[girish_srinivas]

Thanks for the response.

WE are using Neoware Capio Linux based thin client, with 256 MB DDR RAM. mostly people use the VD for Office tools, pdf and basic graphics.

1. We find the diffrence when we do a presentation on the VD with high graphic slides, basic slides with text works fine.

2. When we work with PDF documents, if you use the scroll on the mouse , the video loads line by line and makes the user irate.

3.We have nabled Qos on the MPLS for VD trafffic with 30 k reservation /VD.

[davlloyd]

We were seeing very similiar issues with the Neoware e140, these were addressed by an increase in performance at the client end (revised e140). It is also worth looking at the Wyse V10 as this is a bare bones system that performs very well. Latency and bandwidth can also cause similiar issues although there tends to be other signs as well beyond the rendering of graphics.

Primary differences between the two (apart from ThinOS Linux child vs Linux native) are that the e140 has a PCI slot so can support a VDI card such as the Matrox Epica or the ATI MV2000 where as the Wyse only gives dual VGA (both give VGA/DVI out of the box but the screen quality difference can be a pain for the users).