SG Broadband Community

Got a response! Thanks! You know I'm just keeping you on your toes!

"your argument only goes to prove that IF the server does not have Tcp1323 implemented, then the number we chose would not be a multiple of MSS..."

Hard to argue as I obviously *fully* agree.

And since at this juncture I cannot state with 100% assuredness that the "multiple of MSS" issue is truly necessary for most RWIN's, I am in NO position to recommend you chosing another RWIN number! I also fully agree that the number you have chosen works well, and I see no reason to change it. However, I am not sure that this statement:

"RWIN has to be a multiple of MSS (MaxMTU-40) lower than 65535"

stands up when fully scrutinized. But as always, alternate interpretations of the data are greatly encouraged.

And are you going to ever argue with me about those dang Win95 patches? I may just have to take my toys and go away!

I am also fully investigating the role of TSopts. Robert's post is exceedlingly intriguing. There is a LOT of work for me to do still -- and I have another life off this stupid computer that I have to attend to!

Take care, Philip. I continue to push onward!

[This message has been edited by rmrucker (edited 11-20-2000).]

Mystic- I didn't go to your link yet -- but they sound like they aren't used by MS TCP (I've never heard them described in other of the Microsoft KB's or White Papers...).

Perhaps it's for Unix or something???

Venom- what happened to you? Did I lose you after my long tirade??? Sorry man!

Originally posted by rmrucker:
Mystic- I didn't go to your link yet -- but they sound like they aren't used by MS TCP (I've never heard them described in other of the Microsoft KB's or White Papers...).

Perhaps it's for Unix or something???

Venom- what happened to you? Did I lose you after my long tirade??? Sorry man!

Sorry what I should have stated was that these were for cisco (I think). I was wondering if there was a parallel in MS.

http://www.ieng.com/univercd/cc/td/doc/product/software/ioss390/ios390cg/cgnet.h tm#xtocid35597

Maximizing Throughput
Throughput can be maximized by sending data packets that are as large as the MTU for the local network. TCP uses the Maximum Segment Size (MSS) option to regulate the size of TCP segments transmitted on a TCP connection, which in turn determines the maximum size of packets generated by IP. Generally, sending the largest TCP segment possible is more efficient because the total number of segments transmitted is reduced. However, if the communicating hosts are not on the same network (or subnetwork), intervening gateways might need to fragment the packets, which can be less efficient than sending smaller segments in the first place.

The MSSOPT parameter controls when the local TCP uses the MSS TCP option to increase the size of TCP segments it is willing to receive (the default is the MTU). If permitted, TCP increases its receive segment size to a value that lets the remote TCP send segments that are optimal for the local network and will never transmit a segment larger than that advertised by the remote TCP.

Next to NEVER, MSSOPT(SUBNET) is the most restrictive option because both hosts must be on the same subnet. If the network is not a subnet, or all subnets comprising the local network use the same MTU, or fragmentation is not a concern, MSSOPT(NET) should be used. Otherwise, use MSSOPT(ALWAYS).

also....

Maximum Receive Segment Size
The MSSDEF parameter determines what the maximum receive segment size can be if the MSSOPT parameter does not permit using the optimum value for the local network. This permits using a value larger than the Internet-wide default and smaller than the MTU for the local network. For example, if several local area networks are interconnected by a wide area network whose MTU is smaller than that of the local area networks, MSSDEF should be set to the MTU of the wide area network. When used with the appropriate MSSOPT parameter, TCP can use larger segments while avoiding fragmentation.

The MSSDEF value is specified in terms of the IP packet size and not the actual TCP segment size. In other words, the value specified for MSSDEF should be the largest network packet, excluding the network header but including the normal TCP and IP headers, that can be generated with a maximum size TCP segment.

Just happen to run across this while searching for something else. What are the MSSOPT and MSSDEF parameters? - never heard of them before. Wonder if there is a similar setting for the microsoft tcp/ip stack?

[This message has been edited by Mystic (edited 11-21-2000).]

rmrucker

You haven't lost me yet , I have been busy latley and I have been dying to do some research and I haven't been able to.

But that post explained the missing link to me *lol*.

But hey I keep reading on your post when ever I have a chance lots to learn for me



------------------
\/E(\)()(\/)