Multiple parts here I guess...situation: We deployed 100 or some computers using multicast a week ago. We used 100Mbps setting. We have Gig switches in our IT department and we will only be deploying in there, so we decided to try and bump it to 1Gbps instead of 100Mbps since we were waiting for new machines to arrive. I changed the setting to 1Gbps. Checked the mcsmgr.log and waited for the message .."changes handled" or something like that. After that I restarted the WDS service. This did not seem to help, if anything it may have seemed slower than the 100Mbps setting. I then rebooted the server thinkin maybe it needed something more to be restarted. Normal unicast sends the 6.5GB image in 2 min to the client (just the download part). Using the multicast (autocast) it took longer than 30+ min just for the download (more like 45 but dont want to over exaggerate), not including the extracting and applying. This just seemed crazy so I set everything back to the 100Mbps setting. It is still very slow. It doesn't even \seem to be running like it did last week when we imaged the 100 machines. Something may be messed up. At 100Mbps when I lookat the sccm servers streaming to one client the "svchost.exe (WDS Server)" process said it was sending between 5,000,000 and 9,000,000 B/sec. We now have 30 machines setup and they are downloading at 300,000 B/sec. It has been running since 3:30ish and it is now 6:30. I am remoted so I can't tell if they are still going by the screens but i see the multicast still streaming and no machines have been added to the AD OU I specified so I assume they are still going. I checked the registry here: "HKEY_LOCAL_MACHINE \ SYSTEM \ CurrentControlSet \ Services \ WDSServer \ Providers \ Multicast \ Profiles" as the documetation says here: http://technet.microsoft.com/en-us/library/cc161836.aspx and the "Multicast" folder/key does NOT exist. Is this key there when making changes through SCCM? The entire thing is missing. I looked at a few other threads, http://ctp.social.technet.microsoft.com/Forums/en-IE/configmgrosd/thread/77cb45fe-3302-4daa-9ae3-bfcbf2055cd6 suggested 100:1 ration for WDS Multicast traffic for total to nack and I was 102:1. At this rate I'd be better of using unicast and starting them one by one after each other and just only having 5 downloading simutaneously. It would be WAY faster! HELP PLEASE !!Find this post helpful? Does this post answer your question? Be sure to mark it appropriately to help others find answers to their searches.

So I went through all of my images and on the Distribution settings tab, unchecked multicast. Ensured all images multicast was disabled. Restarted the WDS service. Ran the same image and the download part of the image took 4 min without multicast. The send speed SCCM said was approx 27,000,000 B/sec. I enabled multicast on just the image I wanted to send and then started the imae to one machine. It took like 5:45 using multicast. SCCM reported the send speed was avg/approx 19,500,000 B/sec. Both of these tests were performed using my VMware workstation. I'll try and get in today and try with multiple physical computers and not just one virtual machine.Find this post helpful? Does this post answer your question? Be sure to mark it appropriately to help others find answers to their searches.

Imaging to physical machines is causing the extreme slowness again. going to try and set the stream to wait for "x" number of clients. Edit: waiting for "x" number did not seem to help. Find this post helpful? Does this post answer your question? Be sure to mark it appropriately to help others find answers to their searches.

Still slow when using real clients. Bursts up to 17,000,000 to start with one client. Then slowly trickles down and sits at 4,500,000 forjust one client. Uninstalled Multicast from distibution point. rebooted. reinstalled. rebooted. still same affect. I can run single unicasts slowsly down the line faster then I can multicast. This is ridiculous. I guess I may need to uninstall WDS entirely.Find this post helpful? Does this post answer your question? Be sure to mark it appropriately to help others find answers to their searches.

Wow, no responses... What we ended up doing was: 1. Open regedit 2. navigate to "HKLM\SYSTEM\CurrentControlSet\services\WDSServer\Providers\WDSMC\Protocol" 3. make note of the current value for "ApBlockSize" (mine was 8785) 4. set "ApBlockSize" to 1385 (decimal) Making the packet size smaller seems to have unclogged things for us. It holds steady for one client at 12,500,000 B/Sec and doesn't drop way down. As we add clients however the rate slows. Once we had like 20 clients on it dropped to 2,400,000 B/Sec but at least held steady and didn't drop out of the millions. After all that we disabled Multicast and ran Unicasts to the clients we were deploying as it completed WAY WAY FASTER just by only have 4-6 clients downloading directly at a time. With unboxing new machines this worked well as we were unboxing we start machines into PXE, name them and just trigger the download to start jumping down the line. The remainder of the task sequence could be running while others were downloading. SCCM Multicast needs some work. Find this post helpful? Does this post answer your question? Be sure to mark it appropriately to help others find answers to their searches.

There is no doubt the SCCM Multicast feature was poorly implemented. From day 1 there has been nothing but problems. First it was the 4Gb image size limit due to a 32-bit hash calculation error (http://support.microsoft.com/kb/971413) then it was the settings in the SCCM console not changing the proper registry settings to control the Multicast. (http://support.microsoft.com/default.aspx?scid=kb;EN-US;2419357). For those who used Ghost, it had a nice GUI to monitor and control the multicast but with SCCM, all we have is WDSUTIL to monitor the multicast sessions. Something like this: WDSUTIL /Get-Namespace /Namespace://wdsserver.disney.com/SMSPKGF$/IA100F2F /Show:Clients) If any of you have used it, you know how archaic it is to use in comparison to the Ghost interface. Anyway, to add to Chase's comments, the configuration that worked for me was similar: 1. Open regedit 2. Navigate to "HKLM\SYSTEM\CurrentControlSet\services\WDSServer\Providers\WDSMC\Profiles\Custom" 3. Set "ApBlockSize" = 1385 (decimal) 4. Set "TPCacheSize" = 11190 (decimal) 5. Navigate to "HKLM\SYSTEM\CurrentControlSet\services\WDSServer\Providers\WDSMC 6. Set "DefaultProfile" = Custom 7. Restart WDS Service (WDSServer) Note: If you compare all of the settings for each Profile under the "HKLM\SYSTEM\CurrentControlSet\services\WDSServer\Providers\WDSMC\Profiles" key (10Mbps, 100Mbps and 1Gbps), you will notice the only two values that change are the two values I mention above which control the speed.