20 Feb
2019
20 Feb
'19
8:26 p.m.
On 2/20/19 12:13 PM, Ken Seefried via cctalk wrote:
re: Cisco and IBM protocols
If you're really interested, all of this is exhaustively documented
under the umbrella of Cisco's "IBM Feature Set".
Thank you Ken. That's the type of information I'm wanting to figure out.
There's a *lot* here under the hood, but the last
time I looked
(admittedly, a while) a number of folks had web sites that documented
the correct incantations for Hercules and common hardware.
You can bridge between TR (and FDDI) and ethernet on a Cisco, generally
for non-routable protocols (e.g. NetBIOS); see: 'translational bridging'.
That meshes with what I think I've managed to figure out.
Both SNA and NetBIOS use 802.2 LLC frames with SNAP headers. Token Ring
and Ethernet are able to carry that without any problem. Hence why they
can be relatively bridged bridged without extensively modifying the frames.
If you're trying to get these protocols across an
intermediary 'alien'
network (like the corp FDDI backbone, or the Internet), there are things
like DLSw.
I learned that while reading this week. Now I want to see if DLSw can
be used to connect two Windows machines using NetBIOS across an
intermediary 'alien' network running TCP/IP. }:-)
If you're trying to get TCP/IP from TR to ethernet
and vice versa,
routing generally works better/is simpler (IME),
ACK Bridging between TCP/IP on 802.2 LLC frames with SNAP on Token Ring
to Ethernet II frames on Ethernet is not nearly as simple. Especially
when routing inherently handles it. Even Proxy ARP is a form of routing.
but Cisco has all sorts of bizarre
encapsulation/translation features
for different use cases should you need them.
*nod*
I'm sure I'll find more information than is healthy for me to learn.
You can also make the router look like an SNA
concentrator (PU?).
~whimper~ I don't need to think about that.
I'd love to get a pair of mainframe (VMs?) running in a (non-Parallel)
sysplex between a couple of Hercules instances. The idea of using a
router as an SNA PU is ? intriguing.
--
Grant. . . .
unix || die