The memory integrated network interface

We are designing a zero-copy ATM interface call MINI, the Memory Integrated Network Interface. MR41 has a target bandwidth of I Gbits/sec and will support appli cation-to-application latency of 1.3 microseconds. MINI is a multi-user ATM interface which resides in the mem ory space of the computer system, as opposed to 1/0 space. Applications will have direct access to pages of memory which are used for the network 1/0-, thus appli cations can send and receive packets with no operating system support needed. An application can initiate packet transmission with one memory write; it can determine if a packet has arrived by checking a per-cir cuit control and status word. At the same time, the oper ating system can use MINI for its own communications and for supporting standard networking software. such as TCPAP and NFS. Initial structural VHDL simulations have shown that for single ATM cells we can "bounce'an ATM cell from appli cation to application in a round-trip-time of 39 microsec onds (including pollaig and copy urne on the relaying no&), at a bandwidth of 10 Mbyfts/secW. For 960-byte packets, the bandwidth is 103 Mbytes/second. The architecture of MINI is motivated by our experiences with applications we have run in cluster and computing envimnments. We have used from 48 to 200 computers per application, and have observed dot success ful applications am ones that use the network very bale. The MRSU design is targeted at the kinds of applications we can not curwridy run, those that need to send or receive data at very frequent intervals.