Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!samsung!crackers!cpoint!martillo
From: martillo@cpoint.clearpoint.com (Joachim Carlo Santos Martillo)
Newsgroups: comp.dcom.lans
Subject: Re: WAN Bridge/Router over Fractional T1 (64K)
Message-ID: <11659@cpoint.clearpoint.com>
Date: 5 Apr 91 20:24:47 GMT
References: <1991Mar27.152925.8267@exloghou.portal.com> <1991Mar30.185821.7385@lut.ac.uk>
Followup-To: comp.dcom.lans
Organization: Clearpoint Research Corp., Hopkinton MA
Lines: 70

> The subject kind of says it all, my company is connecting
> two TCP/IP LAN's consisting of mostly of SUN SparcStations by
> a 64K leased line.  I'm looking for a bridge/router that will
> turn these two nets into one virtual net.  We only use TCP protocol.
> I've got reams of propoganda from various vendors, but no first hand testimonials.

Clearpoint Research Corporation makes a high performance ethernet
spanning-tree mac level bridge which can transparently connect two
geographically distant networks via serial connections.  There are two
RS-449 ports which can do at least 64kbps and which can load share when
properly configured.  The RS-449 ports can be jumpered to signal as
RS-232 so that with relatively standard RS-449 to RS-530 conversion
caables the bridge can be connected to RS-232 interfaces. 

> Proposed traffic over the line is about 50M/day, with 75% being
> file transfer, 25% interactive.  It is possible we may increase
> the bandwidth to 128K or 256K over time.

This should not be a problem.  I have run NFS over the serial interface
and have generally barely noticed and then only when trying to load a
tremendously huge program. 

> I guess I'm interested in the product that will give me the best
> through-put for the money.

The Little Dipper gives the theoretically maximum throughput and is very
competitively priced product with lots of neat features like a remote
telnet interface.  I would buy it but then I am one of the designers. 

The Little Dipper has in maximal configuration 8 ethernet interfaces. 
The ethernet interface cards have 3 connectors: MAU, DTE and BNC.  The
connector in use is autodetected.  An ether-TWIP interface is in the
works. 

Depending on configuration, the box has 2 or 3 wan channels.  We
advertize the WAN channels as 64 kbps links but WAN Channels 1 and WAN
Channels 2 use high performance DMA and I have run them at 384 kbps. 
Currently, ethernet packets are bridged serially via simple raw hdlc
encapsulation. 

An imminent software release will support 1984 and 1988 X.25 as well as
load-sharing between WAN Channels 1 and WAN Channels 2 when they are
configured as raw hdlc channels. 

The box supports server and client telnet, responds to ping requests and
has a screen oriented/Forms&Menu based user interface.  The box may be
managed through an RS-232 control terminal port or via an incoming
telnet connection. 

Forwarding between paired ethernet interfaces achieves the theoretical
ethernet maximum of ~56,400 packets with more than enough cycles left
over either to saturate completely serial links which are transmitting
or to receive packets without dropping from a completely saturated
serial link. 

A near term release will support SNMP for management of the ether,
serial, IP and X.25 interfaces.  A slightly more distant release will
support IP routing. 

The current release does filtering at the MAC level.

My phone number is (508)-435-7466.  You may call me.  Of if you prefer
you may send me your address and phone number and I can put you in
touch with a local salesperson.

> Dave St.Clair
> EXLOG, Inc
> dave@exloghou.portal.com

Joachim Carlo Santos Martillo Ajami