BranchCache is a WAN bandwidth optimization technology. Advisable in the case of branch office clients connected to head quarters servers. We can use this along with SharePoint Implementations as well.
Advantages of BranchCache are:
1. It reduces network traffic
2. It increases response time
BranchCache works by obtaining unique hash of documents from server & storing the document along with cache. The next time when user requests the same document, the response time will be faster as the document hash is same, it will be provided from the cache.
There are 2 types of caching in BranchCache:
1. Distributed Cache where multiple clients will store the cached documents & clients will serve each other in providing cached document.
2. Hosted Cache where each client will check the cache for a local server & get the document from cache or server. If from server, it will store a copy in the server for later retrieval by clients.
Let us take a scenario where a 10 MB file is taking 1 minute to download from the server, without BranchCache.
The delay for 100 downloads will be:
1. 1 minute for 1st download
2. 1 minute for 2nd download
3. 1 minute for 100th download
If we apply BranchCache, the delay will be:
1. 1 minute + Cache time for the 1st download
2. 1-2 seconds for the 2nd download (but depends on local n/w speed & request concurrencies)
3. 1-2 seconds for 100th download
BranchCache is optimized when Large Video files, Employee Handbook, Leave Request Forms & other documents which have less chance of modification & more chance for re-downloads.
1. Configuration overheads of clients & servers
2. Although the repeated downloads are faster, the first download increases download time as there is download & caching happening.
Supported operating systems combinations include:
1. Windows 7 clients and Windows Server 2008 R2
2. Windows 8 clients and Windows Server 2012
In this article we have explored a Speed Optimization technique which can be applied for SharePoint 2010 implementations as well.