| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 1927.1 | How channel assignment more or less works. | CGOS01::DMARLOWE | Have you been HUBbed lately? | Tue Jan 24 1995 11:54 | 26 |
| I can answer question 2 right off the bat.
You cannot specify which channels (wires) to use in the backplane.
Ethernets are created from the top down, ie. Flex channel on upper
connector first and 5 more on the lower connector (channels 1, 2, 3, 4
and 5). FDDI's are created from the bottom up. The hub manager
selects the wires or channels based on what you want created. For
things like FDDI, the hub manager could select one of the half channels
based on the fact that the point to point link is from slots 1-4 or
5-8. If the point to point link crosses the 4-5 split then the
hub manager would use channel 10 or 9 or 8 or ....
HUBWATCH only displays the LAN's you have created with no regards to
actual replacement of the LAN's on specific channels. That is why you
can have an FDDI displayed as the first LAN (or channel) when in fact
it is really the last channel in the hub.
Not only that but you can create 7 or more Ethernets on a DH 900 with
Hubwatch. The hub manager doesn't assign channels or wires until you
actually connect a module to that LAN. It only counts wires or
channels that could be used. Having created 8 Ethernets though, the
hub manager will only allow the first 6 used to actually work. The
remainding 2 will not be used as present Ethernet modules can only use
the first 6 Ethernets. Confused?
dave
|
| 1927.2 | More about question 2. | NETCAD::GALLAGHER | | Tue Jan 24 1995 12:45 | 21 |
| More on questions 2. .-1 is a good description, but I'd like to
reiterate a few points.
HUBwatch doesn't know or care about which flex-channels are used.
HUBwatch communicates with the Hub Manager (aka Management Agent
Module, aka MAM) to make and break connections.
The goal of the Hub Manager's matrix allocation algorithm is described
as, "Match the least flexible connection requests with those signals
which have the fewest other potential uses." The Hub Manager
retrieves information about a modules ability to connect to the
flex-channels. From this information is determines port "flexibility"
and "signal set utility".
I only mention the gory details of the algorithm to stress that
although .-1 does a good job of describing what is done today, based
on the modules we have today, the Hub Manager can handle new modules
which break any and all of these "rules". For example, someday there
may be an Ethernet module which can connect to all of the flex-channels.
-Shawn
|
| 1927.3 | and Question 1 | SLINK::HOOD | I'd rather be at the Penobscot | Tue Jan 24 1995 15:11 | 12 |
| And as for question 1...
The DECswitch 900EF (and the DECswitch 900EE and the DECbridge 900MX and
the PEswitch 900TX and the RoamAbout Access Point) doesn't currently support
different source/dest filters. What actually happens (as is suggested by
HUBwatch) is that the protocol or address is not allowed to pass to/from a
specified LAN.
It's an all-in-one combo of source/dest.
Tom Hood
HUBwatch
|