Kacheong Poon wrote: > Paul Durrant wrote: > >> Why? If a the DB_LSO flag is not set then the driver/hardware must not >> fragment the segment. Hence the stack can send segments of any size it >> likes and not have the driver/hardware interfere. > > > The issue is about whether the hardware can segment > the large piece of data into segments of different > sizes. I understand that TCP can send down different > sizes of segment and ask the hardware not to segment > them. But this is basically the same as today, send > down one segment one time. What I am referring to is > the ability to send down a large piece of data and ask > the hardware to segment it into different sizes, say > one large and then three shorter. This is one way > how TCP can find out if PMTU has changed. Theoretically, it's not impossible. *Assuming* it's valuable, TCP can pass down this requirement along with other LSO information, Extended SOFT LSO can handle it easily before hardware LSO. But, what value do you see with such implementation?
LSO is not implemented for every single transmission, but for a "stable" transmission that doesn't involve PMTU-like "trick", since such rare case won't impact performance much. :; Thanks, Roamer -- # telnet (650)-786-6759 (x86759) Connected to Solaris.Sun.COM. login: Lu, Yunsong Last login: January 2, 2007 from beyond.sfbay [EMAIL PROTECTED] v1.04 Since Mon Dec. 22, 2003 [EMAIL PROTECTED] Networking]# cd .. _______________________________________________ networking-discuss mailing list [email protected]
