But TCP connection do not need to pre-allocate recv buffers like RDMA does. If all RDMA connection attributes can be modified without beraking a live connection, like RDMA read credits, then analogy with TCP will work. Arkady
Arkady Kanevsky email: [EMAIL PROTECTED] Network Appliance phone: 781-768-5395 375 Totten Pond Rd. Fax: 781-895-1195 Waltham, MA 02451-2010 central phone: 781-768-5300 > -----Original Message----- > From: Sean Hefty [mailto:[EMAIL PROTECTED] > Sent: Wednesday, October 19, 2005 1:38 PM > To: Kanevsky, Arkady > Cc: Richard Frank; [EMAIL PROTECTED]; > [EMAIL PROTECTED]; [email protected]; > Davis, Arlin R > Subject: Re: [dat-discussions] RE: [openib-general] Re: iWARP > emulationprotocol > > > Kanevsky, Arkady wrote: > > if look at the proposal it shows 2 ways to address this. > > I did notice this. > > > 1. Have 2 protocols. > > One just send SRC IP address and port, and provdie 64 bytes to ULP. > > Another one send both SRC and DEST info and leaves 48(+-) bytes of > > private data for ULP. > > If the goal is to make the mapping from IP address to IB > address transparent, > then I think we want a single protocol. Ideally, the > application shouldn't need > to know if they're connecting over iWarp, IB, or any other > RDMA NIC. Any > solution that makes IB appear different than iWarp makes this > more difficult to > accomplish. > > > 2. Have 2 protocols. > > Split IPv4 and IPv6 methods. > > Same issue as above. This makes IB connections appear > differently than an iWarp > connection. This is why I asked if the destination address > is required. If it > is, then the applications need to make do with less private data. > > > For IPv4 send SRC and DST addressing and 64 bytes of ULP > private data. > > For IPv6 we have several options. a. GID=IPv6 address > > Unless an IP packet can be sent to a GID and be processed, I > don't consider a > GID equal to an IPv6 address. I also don't think that we > should require system > administrators to add GIDs to IB ports just because they want > to add an IP > address to a system. > > > b. use second CM frame to have carry ULP private data. > > An application can make due with no private data. They can > transfer whatever > data that need once the connection has been established, like all TCP > applications do. Adding more CM messages to pass the same > data that should be > passed over the user's QP is the wrong approach. > > In fact another alternative is to make all CM private data reserved. > > - Sean > _______________________________________________ openib-general mailing list [email protected] http://openib.org/mailman/listinfo/openib-general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
