KCM@BYUADMIN.BITNET (Kelly McDonald) (11/06/87)
I haven't posted a general message about the technique I used to encapsulate IP packets in Netbios for the ka9q code, so here goes: I figured that since IP is best effort delivery, there wasn't much point in using the session fetures of Netbios. Therefore I chose to implement using the Netbios datagram functions. There is a limitation of 512 bytes on datagrams, but this didn't pose a problem with ka9q because it supports IP fragmentation. I didn't need to use any ARP for IP to Netbios translation because the Netbios name is constructed to be "TCPIPnnnn" where nnnn is the stations IP address in binary. Therefore when an IP datagram needs to be sent, it is sent directly to the destination based on the destination address in the IP header. I have found with the ka9q code (in our environment, PC on an ethernet, through a bridge to a NAS 9000 running Wiscnet) that I get about 4k/sec using ftp. Through the PC on the ethernet into netbios, I get about 3k/sec, which seems somewhat respectable considering the PC net is a starlan and I'm running over netbios. I think that other protocols could be implemented over netbios in a similar fashion. I'm hoping that the use of netbios datagrams will improve the performance over the session support of netbios. Netbios was chosen (rather than IPX on our Novell networks) because of the wide utilization of it. Novell seems to have done a respectable job of emulating netbios in their networks. I'm wondering if an additional ka9q driver could be written that uses the appletalk DDP protocol so that we could replace these $2500 kinetics gateways with a PC running ka9q. It would be nice to have a pc sitting on the ethernet that gateways both a novell lan as well as an appletalk network. Has anyone had experience with the TCP/IP encapsulation that has been done over appletalk with the mac stuff from CMU? Can anyone post the protocol?
ddl@husc6.UUCP (Dan Lanciani) (11/08/87)
In article <8711051843.aa03370@Louie.UDEL.EDU>, KCM@BYUADMIN.BITNET (Kelly McDonald) writes: > I'm wondering if an additional ka9q driver could be written that uses > the appletalk DDP protocol so that we could replace these $2500 > kinetics gateways with a PC running ka9q. It would be nice to have > a pc sitting on the ethernet that gateways both a novell lan as well > as an appletalk network. Has anyone had experience with the TCP/IP > encapsulation that has been done over appletalk with the mac stuff from > CMU? Can anyone post the protocol? I have written a ddp/ip driver for MIT/CMU PC/IP. It talks through the new TOPS driver (presumably compatible with Apple's PC card). Source is available for anonymous ftp from husc6.harvard.edu in pub/ddl/atip or from harvard.harvard.edu in ddl/atip. Note that the ip-over-ddp system is not symmetrical between gateway and client so more code would be necessary to turn this into a kinetics box replacement. Dan Lanciani ddl@harvard.*