Re: MIDRANGE-L Digest V4 #364

The serial ports *don't* have a MAC address.  Motorola routers
are very smart and can do a lot of things in their software.  One of
the things they do quite well is encapsulate serial communication over
TCP/IP with their own proprietary encapsulation scheme.

So, lets take your main office.  It will have connected the Frame Relay
circuit, into a certain port, which is given a DLCI number (Frame Relay
circuit id number).  It will have the ethernet port.  It will have the
two serial ports.  
The Motorola router will take the ethernet address and redirect it out
the Frame Relay port to whichever DLCI the IP address for that packet is
addressed to.  It will take Serial # 1 and direct it out of the Frame Relay
port directing it to a certain DLCI (perhaps the DLCI of your Area Office # 1).
Then it will take Serial # 2 and direct it out of the Frame Relay port to the
DLCI of office # 2.

Now nets look at your Area Office # 1.
It's router will have the frame relay connection assigned a DLCI number, an
ethernet port, and a serial port.  It will look at the header for incoming
packets to see where to send them.  It will grab the encapsulated serial
packets and send them to the serial port.  It will take the ethernet packets
and send them to the ethernet port.  It will map outgoing the other way 
around.

This is all done in the Motorola Programmable Routers.  The actual device
plugged into the serial port doesn't know it's talking to a router and not
an actual machine, nor does it care, nor does it have a MAC address.

You are going to have to find Cisco equipment that encapsulates Serial over
Frame Relay, although they may not have one.  In which case you are going
to either come up with some other way to get the serial communication over
frame relay, or stick with the Motorola equipment.

Time to talk to a Cisco sales rep.

Incidentally, the reason I know all this is because I went to Motorola 
University
for a week one time to learn how to program the Motorola 6500 series 
programmable
routers.  And then I never did get the opportunity to ever program one.  I'm 
glad
my knowledge is good for something!

Regards,

Jim Langston

Date: Wed, 11 Apr 2001 12:52:08 -0500
From: "Roger Vicker, CCP" <rvicker@vicker.com>
Subject: SDLC & Network configuration Help?

Help?

I have a customer in the process of swapping their Motorola routers
(on Sprint Frame Relay) out in favor of Ciscos. Sprint is providing
the equipment and now are asking a question I can't seem to answer.

Here is the Configuration as it now stands.

Main Office:
    AS/400
        Serial Port with SDLC for Area office #1
        Serial Port with SDLC for Area Office #2
        Ethernet port

    Area Office #1
        AS/400
            Serial Port with SDLC to Main Office
            Perle 494 Serial Port with SDLC to Main Office (5
cards/controllers)
        Ethernet Lan

    Area Office #2
        Perle 494 Serial Port with SDLC to Main Office (2
cards/controllers)
        Ethernet Lan

The Main Office AS/400 serial ports plug directly into the router. The
Ethernet obviously goes to a hub for the LAN and then to the hub. Area
Office #1 AS/400 and Perle serial ports plug directly into the router.
They are changing the router to add the Ethernet connection. Area
Office #2 Perle serial plugs directly into the router and the LAN has
a cable from the hub to the router.

Specifically the Area Office #1 AS/400 and the Perle appear to the
Main Office AS/400 as a multi-drop lease line separate from Area
Office #2.
Area Office #2 Perle appears as another multi-drop lease line.

The Perles do not appear to have an exchange ID. However the AS/400's
do. The main office AS/400 has the same exchid on both line
descriptions. The Area Office #1 has a different exchid in the
controller and its actual config devices have the swap between line
and controller exchids.

All three sites will have the Ethernet LANs tied together to access
the Main Office AS/400.

Sprint is asking "What is the MAC address of the serial ports?"

I've never heard of a MAC for SDLC. Does anyone know how to determine
this or have a Sprint contact that I can get our Sprint contract to
talk to?

Thanks.

Roger Vicker, CCP

- --
*** Vicker Programming and Service *** Have bits will byte ***
www.vicker.com ***
Monday: The day after the football game.
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