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Conference netcad::hub_mgnt

Title:DEChub/HUBwatch/PROBEwatch CONFERENCE
Notice:Firmware -2, Doc -3, Power -4, HW kits -5, firm load -6&7
Moderator:NETCAD::COLELLADT
Created:Wed Nov 13 1991
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:4455
Total number of notes:16761

2761.0. "DECswitch900EF Novell translation question" by DECPRG::PAVLUP () Fri Sep 15 1995 08:19

Hi all specialists in Novell networks!

May I have a question that could sound naive but I need an answer to properly
handle some customer's question...

The point is related to DECswitch 900EF, and the way how the translation 
between Ethernet and FDDI frames is done. And the particular questions that a
customer raised are:

- What happens in a network in which there are several Novell encapsulations
  used on the Ethernet sides?
- Considering that the Raw-Ethernet is switched on the per-box basis, how 
  DECswitch 900EF handles a situation in which more than one encapsulation
  is used on its Ethernets?

Can anyone who knows these issues by heart spend few minutes explaining how
are the translating issues solved in the DECswitch (and probably generally)?
I'd appreciate all responses! 

Thanks a lot in advance
Petr Pavlu.
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2761.1NETCAD::B_CRONINFri Sep 15 1995 15:3819
    
    The answer is that you can't have multiple hacks to make netware
    work. You pretty much have to choose one vendor and stay with that
    vendor unless you have the time to study this on a vendor by
    vendor basis. It is possible, for example, to put all the station 
    running RAW802.3 behind one bridge, and all the stations running
    Ethernet V2 behind a different bridge, as long as the format on the 
    FDDI is the same. That way the bridge converts for the FDDI frame to 
    the locally preferred protocol. 
    
    Customers can solve the generic problem by converting their end nodes
    to use Ethernet frame formats, or 802.2/802.3 formats everywhere. Yes, 
    this is painful for them, and in some cases hardware is not upgradeable, 
    but its the only way to ensure multivendor interoperability. 
    
    Please remember that this is Novell's mistake, not ours. We did our
    best to make something that was usable, not solve the larger problem 
    of how to make a standard implementation. In fairness to Novell,
    they no longer recommend that people use RAW802.3
2761.2Thanks, I see the point.DECPRG::PAVLUPMon Sep 18 1995 06:479
    Thanks for comments! I also found an interesting overview of
    implementation in 1511.7 which shows what you say on particular
    encapsulation types. 
    
    I think I have enough information for now.
    
    Thanks and regards.
    
    Petr.
2761.3I'm sorry - one more thing to clarify...DECPRG::PAVLUPMon Sep 18 1995 07:1918
    Now when talking with the customer, one more point has occured to me
    which I don't see how it is done.
    
    You mentioned in .1 "locally preferred" protocol. If we forget for a
    while the broken Novell "Raw 802.3", how generally the switch 900EF
    solves the problem of potentially various Ethernet protocols on the
    Ethernet (but in fact also on the FDDI) side? I mean if there are three
    stations running Ethernet II, 802.2 SAP, and 802.2 SNAP, how does the
    switch ensure each station understands its protocol and gets the right
    data?
    
    Is there a multiple transmission? Or a kind of table? 
    
    Thanks for clarifying this for me.
    
    Regards Petr.
    
    
2761.4Eth-FDDI Table in 2567.1SNOFS1::KHOOJEANNIEHumpty Dumpty was pushedFri Sep 29 1995 03:392
    Petr, there is a DECswitch table in Note 2567.1.