What is BNA

Wolfgang Banholzer

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Sep 20, 1996, 3:00:00 AM9/20/96

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I have to filter a BNA on a bridge.
Until now i never heard from BNA.
So can somebody tell me, where i can find information about BNA, what it
is and how it works.

Thanks a lot

Wolfgang Banholzer
ba...@siemens.ch

GRIPPER

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Sep 21, 1996, 3:00:00 AM9/21/96

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City code for Nashville?

Wolfgang Banholzer <ba...@siemens.ch> wrote:

>Thanks a lot

>Wolfgang Banholzer
>ba...@siemens.ch

MAO

*************************************
*** No good deed goes unpunished! ***
*************************************

barrie brook

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Sep 23, 1996, 3:00:00 AM9/23/96

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BNA is a proprietary Unisys networking architecture (Burroughs Network
Architecture). It has a couple of protocols that will operate over industry
standard bridges and routers: IEEE 802.3, in two flavours, Class of Service 1
and class of service 2; and BNA/IP, where BNA is carried in an IP packet
(not in a TCP packet). If you have to filter these, then I would want to
know what BNA protocol is being used in your case, before suggesting a
filtering option for bridging. If BNA is using IP, then it's quite
straightforward, as BNA is assigned IP protocol ID 49 (hex 31).

Please let me know the details you need and what you are trying to accomplish,
and I will be pleased to add more information.

Regards,

Barrie Brook
Unisys, WWT, Malvern
Barrie Brook
WWT, Malvern 215-993-7365 N2 322-7365
S...@trpo5.Tr.Unisys.com

Keith Stone

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Sep 24, 1996, 3:00:00 AM9/24/96

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In article <51vi95$6...@news0-alterdial.uu.net>, GRI...@AOL.COM wrote:

>City code for Nashville?
>
>Wolfgang Banholzer <ba...@siemens.ch> wrote:
>
>>I have to filter a BNA on a bridge.
>>Until now i never heard from BNA.
>>So can somebody tell me, where i can find information about BNA, what it
>>is and how it works.
>
>>Thanks a lot
>
>>Wolfgang Banholzer
>>ba...@siemens.ch

Bad Network Architecture?

Mike Kain

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Sep 25, 1996, 3:00:00 AM9/25/96

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In article <kstone-ya0230800...@news-server.interpath.net>, kst...@crewstone.com
says...

Actually, BNA has some very good pieces, that other networks (read IP)
don't. For example, the BIAS router is a totally adaptive router between
clusters (yes, someone thought of them way before Micro$oft) with well
defined message priorities. I dare IP to do that.

The port level, well, is another story......

Mike Kain
Principal Software Engineer, Networking Products Organization
HMP/A Series Software Engineering, Unisys Corporation, Paoli, PA.

(Yes, Larry, I spelled it right ;) ;) ;)

barrie brook

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Sep 27, 1996, 3:00:00 AM9/27/96

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Just for information, here is the dialog resulting from the original
submission. It might just be useful to other too.

From: Wolfgang Banholzer
To: Brook, S. Barrie TR
Subject: Re: BNA over bridges
Date: Tuesday, September 24, 1996 3:03PM

Hi Barrie

Thanks a lot for your information.I think that was exactly what
i was searching for. Next time i will try it, and i think it will work.
If not, i will ask you again.

Regards

Wolfgang

At 13,00 23.09.96 EDT, you wrote:

My first assumption is that you are connecting BNA nodes together over
the bridges (CP2000 or A Series systems).

(If you are connection lan workstations, using IPX/SPX, then
that's a completely different situation, which I have not addressed
that here.)

BNA uses the IEEE 802.3 standard and not Ethernet. Therefore,
there is no type field. 802.3 uses the "Type" field as a
"Length" field, so you won't be able to do a simple filter by "Type."

The BNA 802.3 header should look like this for CP2000 connections;

destination "ethernet" address - 08 00 0b fx xx xx
origination "ethernet" address - 08 00 0b fx xx xx
length (ethernet type field) - all sorts of values here
(see also note below)
DSAP - 04 (or 05)
NSAP - 04 (or 05)
Control - various
BNA header (various)

After this there are more various combinations, but nothing that
I would consider unique for all BNA frame types.

If you can mask filter the "ethernet" addresses you should be ok.
If not, then you'll have to filter specific addresses. If the
BNA nodes are all configured for 802.3, then the length fields
will all be less than 1500 and you may be able to filter out
all other types that can be encountered. If the BNA nodes are
configured for CPLAN (a proprietary "ethernet" format) then the
length field is byte reversed and you can get values that look
like type fields (>8000).

A Series host systems have the same format as the CP2000 but their
"ethernet" addresses can be configured to any value. So, if you
only have to bridge A Series, their addresses could be made to be
filtered easily.

WARNING: Bridging BNA can be hazardous to your health. Because
bridges often have little or no buffering, BNA traffic can overrun
the wide area capacity and cause very poor performance. This can
be fixed by using better bridges or by using 802.3 Class of
Servce 2 (COS2), which has a windowing scheme at the 802.2 layer.
Using COS2 allows the lower layers to flow control the ammount of
traffic to the bridges and recovers lost packets more quickly than
higher layers.

Also, if CP2000s need to be loaded over the bridges, then the
downline load parameters in the CP2000 must be set to match
your needs (802.3 or CPLAN).

Also, if you have a large bridging network, spanning tree updates
can be very disruptive. Avoid spanning tree if at all possible.

We still run a large amount of BNA traffic over bridges and do get
good performance.

I hope this helps.

If you need more information, please let me know.

Barrie Brook
Unisys
WWT, Malvern

From: Wolfgang Banholzer
To: Brook, S. Barrie TR
Subject: Re: FW: fyi -
Date: Monday, September 23, 1996 4:31PM

Hi Barrie

Thanks for your mail. As soon as i know, there is BNA which
is not using IP. We had to configure bridging on our routers
to transport BNA. Without bridging, there is no connectivity
between the stations which are using BNA. The problem now is,
that with bridging, i have all the other traffic on the leased
lines, so i have to write a filter on the bridges, which allows
only BNA. This means that i need an Ethernet-Type-Code, to
which i can filter. For any reasons i do not want to filter the
MAC-Adresses of the BNA-Stations. Let me know if you need
further information, and i try to find it.

Regards

Wolfgang

At 09,33 23.09.96 EDT, you wrote:

Wolfgang,

BNA is a proprietary Unisys networking architecture
(Burroughs Network Architecture). It has a couple of protocols
that will operate over industry standard bridges and routers:

IEEE 802.3, in two flavours, Class of Service 1 (COS1)and
Class of Service 2 (COS2); and BNA/IP, where BNA is carried

in an IP packet (not in a TCP packet). If you have to filter
these, then I would want to know what BNA protocol is being
used in your case, before suggesting a filtering option for
bridging. If BNA is using IP, then it's quite straightforward,
as BNA is assigned IP protocol ID 49 (hex 31).

Please let me know the details you need and what you are
trying to accomplish, and I will be pleased to add more
information.

Regards,

Barrie Brook
Unisys

WWT, Malvern

Barrie Brook
WWT, Malvern

S...@trpo5.Tr.Unisys.com