Please excuse me if I am asking this in the wrong forum. I am trying to respond to a customer's question concerning when to put in place an SCCM feature for bandwidth conservation, such as a BDP, or Sec. Site w/ MP and DP. One obvious answer is, "When you are concerned about bandwidth", but I hope to give a little more detail than that. Please read my proposed response below and let me know whether I am going down the right path or should include/remove details. Thanks in advance. -------Proposed response---------- I have found no official guidelines on thresholds for determining when to implement a method of bandwidth conservation, such as a secondary site with a DP or the use of a branch DP. The decision must be made around the following points: Available bandwidth between clients and site system (DP and/or MP) Number of clients A rule of thumb for estimating non-BITS client bandwidth use when downloading content from a DP is ~30MB/s. This assumes the client uses ~ ¼ of the available 120MB/s (1Gb/s = ~120MB/s) for the file transfer. So if the client is downloading 2 GB of content (avg. Win7 Image) from a DP across a 100Mb (12.5 MB) WAN link then that 1 client will completely consume the WAN bandwidth for ~3 minutes. Using BITS and GPO settings we can limit the bandwidth each client can use for downloading content (assuming our DPs are configured to allow BITS downloads). I recommend use these GPO settings for client PCs in sites without a DP/MP. I still haven’t answered your question…it really should be answered on a case-by-case basis looking at the available bandwidth/# of clients in each site. For a general rule, we could say any site with more than 25 client PCs and less than 100 Mb of available bandwidth should be set up as a secondary site with a single server functioning as the MP/DP/SUP/etc. All sites without a local DP should use BITS with GPO-based bandwidth throttling to ensure we don’t overrun the WAN link for extended periods during deployments. --------end proposed answer-------------

I would say that's a pretty good response. There's is a tool from Microsoft that can be used for sizing but I don't find it very useful. I would say any site where you plan to do OSD needs a site server. You do not want to do OSD over the WAN. I have had customers place a server anywhere there is at least 10 clients. I have had others place a BDP anywhere there are 3 clients. Some have WAN accelarators and are far less concerned about bandwidth because of that. If you are using Win 7 you can use peer-to-peer caching. If you are not using Win 7 take a look at something like OneSite from Adaptiva if you want to have less servers. It all boils down to there's no one answer that works for every customer. John Marcum | http://myitforum.com/cs2/blogs/jmarcum |

Very helpful reply, John. Thanks very much. Steve