John, Last Question First: Q: My understanding of HTTP compression is it must be done on 2 ends to be workable. A: Ok, here is how this works, In HTTP 1.1 there is a standard for compressing HTTP responses. Basically, the browser says: "I accepted encoding, give me an encoded page if you can". It does this by sending an "Accept-Encoding: gzip" HTTP request header. Gzip is the type of encoding it will accept. It also request encoding called deflate -- they are both very simliar. When the server gets this it can deciede to compress the response or not. If it does compress it, it sends a response header like this "Content-Encoding: gzip". When the browser recieves this response header it it knows that the page in compressed (looks like binary garbage in your TCP/IP trace), the browser then decompresses the response and renders the uncompressed page. With gzip/deflate you can get a 80% reduction in your page, making it faster on latent networks and saving you bandwith costs. So the answer is the browser knows how to decompress all you have to do is provide compression. With the XCompress for ISA, compression is done on the ISA server by our filter. Q: What is the purpose/benefit of compressing at the firewall? A: Well firewall compression might not be that interesting, unless you are using your ISA server for a reverse proxy or forward proxy. Let's say your ISA is set up as a proxy server for the outbound Internet at your Coporate headquarters in New York, and you have a WAN where your branch office is in LA. The branch office connects via a partial frame via VPN to coporate that provides outbound access. If you install XCompress for IIS in NY, it will compress all the Internet responses from the outside, making the partial frame faster, and the VPN encryption quicker. Or, you have a ISA server in front of your web server, as a firewall/proxy/cache, and you want to compress that traffic before it leaves your data center. Install XCompress for IIS, and the outbound traffic is reduced and your bandwidth bills goes down. Q: How will that speed up traffic or reduce bandwidth usage? A: Is this question answer by the above? -Wayne -----Original Message----- From: John Tolmachoff (Lists) [mailto:johnlist@xxxxxxxxxxxxxxxxxxx] Sent: Friday, July 09, 2004 1:24 PM To: [ISAserver.org Discussion List] Subject: [isalist] RE: XCompress for ISA -- Compression Filter http://www.ISAserver.org Replying to list for discussion purposes. What is the purpose/benefit of compressing at the firewall? How will that speed up traffic or reduce bandwidth usage? My understanding of HTTP compression is it must be done on 2 ends to be workable. John Tolmachoff Engineer/Consultant/Owner eServices For You > -----Original Message----- > From: Wayne Berry [mailto:wayne@xxxxxxxxxx] > Sent: Friday, July 09, 2004 1:12 PM > To: [ISAserver.org Discussion List] > Subject: [isalist] XCompress for ISA -- Compression Filter > > http://www.ISAserver.org > > ISAList: > > I will take just a second to blow my own horn and try to get some Beta > Testers. We (XCache Technologies) have developed an ISA filter that > performs HTTP compression on traffic going through the ISA server in > both directions. > > Basically, HTTP compression is what Google and a bunch of other > companies are using to speed their pages and decrease their bandwidth > and it doesn't require any client side code -- the browsers know how > to decompress since it > is part of the HTTP 1.1 standard. > > I am looking for a few Beta testers that would like to try the > product, we have developed in conjuction with Microsoft and they are > testing it already > for us. Just write me off the list. > > Kind Regards, > Wayne Berry > Developer > XCache Tech > http://www.xcache.com > > > > > > ------------------------------------------------------ > List Archives: http://www.webelists.com/cgi/lyris.pl?enter=isalist > ISA Server Newsletter: http://www.isaserver.org/pages/newsletter.asp > ISA Server FAQ: http://www.isaserver.org/pages/larticle.asp?type=FAQ > ------------------------------------------------------ > Other Internet Software Marketing Sites: > World of Windows Networking: http://www.windowsnetworking.com Leading > Network Software Directory: http://www.serverfiles.com > No.1 Exchange Server Resource Site: http://www.msexchange.org Windows > Security Resource Site: http://www.windowsecurity.com/ Network > Security Library: http://www.secinf.net/ Windows 2000/NT Fax > Solutions: http://www.ntfaxfaq.com > ------------------------------------------------------ > You are currently subscribed to this ISAserver.org Discussion List as: > johnlist@xxxxxxxxxxxxxxxxxxx > To unsubscribe visit > http://www.webelists.com/cgi/lyris.pl?enter=isalist ------------------------------------------------------ List Archives: http://www.webelists.com/cgi/lyris.pl?enter=isalist ISA Server Newsletter: http://www.isaserver.org/pages/newsletter.asp ISA Server FAQ: http://www.isaserver.org/pages/larticle.asp?type=FAQ ------------------------------------------------------ Other Internet Software Marketing Sites: World of Windows Networking: http://www.windowsnetworking.com Leading Network Software Directory: http://www.serverfiles.com No.1 Exchange Server Resource Site: http://www.msexchange.org Windows Security Resource Site: http://www.windowsecurity.com/ Network Security Library: http://www.secinf.net/ Windows 2000/NT Fax Solutions: http://www.ntfaxfaq.com ------------------------------------------------------ You are currently subscribed to this ISAserver.org Discussion List as: wayne@xxxxxxxxxx To unsubscribe visit http://www.webelists.com/cgi/lyris.pl?enter=isalist