SUMMARY: 56K lines

From: John Mc Grath (ext-adm!jmcgrath@uunet.UU.NET)
Date: Thu Mar 31 1994 - 11:02:37 CST

Sorry for the delay, but I wanted to be sure of what we were going to
do before I sent out the summary.

As of this morning the cost exceeds the need. So we are not going to do
it. However the net came thru with a lot of great information. First, my
original request, then the replies.

> Sun Managers,
> Please forgive my lack of knowledge on this subject, but up until
> now I have had responsibility for only local area nets connected by modems and UUCP. Today my boss has decided, due to a major increase in traffic, to lease a high speed dedicated line(T1 or 56K) between two of our remote networks to replace the current 9600 modem dialup.
> Unforgivably, I know nothing about setting up this high speed line.
> So, I turn to the people who know for a short burst of knowledge
> about the where to look for setup info, pitfalls and tips.
> Am I correct in assuming (I know what the word means.{8-}) that I can use this line as an ethernet line and NFS mount files across it?
> Tks
This probably is NOT what you want to hear, but ...

My recommendation is that this will be a difficult thing for you to set up,
with little or no previous experience in this. You need things like routers,
CSU/DSUs, and digital equioment. Also, if you have any voice tie lines, you
could save yourself a lot of money by combining them with the data onto the
T1 (or creating tie lines; how far apart are these two sites)?

You could do it, but based on my own experience, you'll end up spending more
time and money then if you had an expert do it.

So, now the pitch ... I do this sort of thing for a living. I've built and
installed a network of T1s and routers all over the world. I'm not going to
push myself any more, unless you want to hear more. :)

uunet!!mann (Mark Mann)

Get the book:

        TCP/IP Network Administration
        by Craig Hunt
        Publisher O'Reilly & Associates
        ISBN 0-937175-82-X

It's a great introduction & practical manual for basic network

uunet!!glenn (Glenn Satchell - Uniq Professional Services)

Depending on what protocols, yes you can consider it like a bit of
ethernet. NFS, rlogin, telnet, etc will all work.

You will need to high speed serial interfaces, one for each end. Sun
makes a HSI/S sbus board which will give you four interfaces with a
total throughput of ~3Mb/s, so 56k will be easy. The built in serial
interfaces will not support 56k.

Then you need some software, preferably PPP. Again Sun has Sunlink PPP
(1.0 for 4.x, 2.0 for Solaris 2) or try Morningstar or Brixton for
other PPP implementations.

Basically you set up each site as a different subnet and then the two
suns will act as routers between them.

Alternatively you could consider buying a dedicated router like a Cisco
which will handle the PPP directly.

uunet!NUCMED.MED.NYU.EDU!hkatz (Henry Katz)


you ask 2 totally separate questions. setting up a dedicated leased line
is a religious question for which many solutions exist depending on your
criterion, need, location and budget. eg. if you're near a NETCOM pop it
could cost you as little as $1k/mo for the line (plus initial equipment
costs - routers, CSU/DSU, etc..) it is best to look for FAQ on groups. as to nfs - yes you can mount files across it.
of course your mileage will vary with many things.


uunet!mako.Newbridge.COM!brobbins (Bert Robbins)

Depending on the distance between the sites and the security required you
may want to consider one of the Internet providers, UUNET, PSI or others.

If security is your main concern then go with a dedicated link. NFS at 56kbps
is almost tolerable but is better at T1. You will need some type of bridge or
better yet routers at each end. Routers at each end will cut down on the
unnecessary traffic if the link is only 56kbps.


uunet!!don (Don Baune 581-6088 MIRL)

I have done this two ways.

A. Use a pair of two port routers (now less then $2,000 each end) and the
two segments look like different subnets and has worked VERY well. After
setting the switches on the CSU/DSU's and configuration of the routers I
haven't had any additional work.

        Router Phone Link Router
        | CSU/DSU | CSU/DSU |
Net A Net B Net C
110.128.60 110.128.61 110.128.62

B. Use the Sun with the high speed serial interface card and let the sun do
the routing. After the cost of the High-speed serial card and SLIP/PPP software
(The card is needed if you want to run any faster than 19.2 as this is all that
will support their internal serial lines at) the router solution didn't look to
costly. The problem here was that I could only run IP since this all that sun
would route. Additionally I have the ongoing headake of keeping the PPP link up.
This is an on going battle os the OS gets updated.

If you can afford it look at the T1 link, a 56K can get eaten up in a hurry
with NFS mounts. Our T1 was less than two 56K's. Make sure your CSU/DSU are
the same it sure makes connecting together a lot easier. (there are similar
to modems but are for the t1 and 56K digital lines)

When I was getting things up and running it helped to have a dummy T1 line
to connect everything together in the office first and then I took the
remote equipment out to the site and it just plugged in. This dummy line
is similar to what you would use to connect two 10BaseT porst together.

Hope this helps,

Christian Lawrence <uunet!!cal>

you can use your Sun for the higher speeds provided you have an HSI/MCP card.
However, I would recommend buying a dedicated piece (actually 2) of network
equipment that specifically handles signal conversion buffering, recovery.
Examples would be a router (cisco, wellfleet, etc.) or probably more
appropriately - a bridge/convertor such as TransLan from VitaLink. These boxes
take Ethernet in and T1 or fractional T1 out. There are many vendors with
products in this category. Call up your favorite network equipment vendor
and ask them about solutions and comparisons to other products. Then call the
other guys and compare price/features.

At 56 kb, you will have to adjust transmission parameters to compensate for
transmission delays, packet sizes, error rates, etc.. As you approach T1, you
will see VERY favorable performance without any such changes.

Robert Ogren <uunet!!rmo>

Yes you can setup nd run NFS/Automounts across. But now you will
have to get a router and setup routing information about your domain.
Cicso makes a 4000 model that will allow you growth for the future
or you can get a 3000 model which straps you into a fixed configuration.
ex: 3000, One HS Serial interface and an ethernet interface. No other

ex 4000, you can use 2 HS Serial , Two ethers or combination of others


And many more.

|John J. Mc Grath E-mail: uunet.UU.NET!ext-adm!jmcgrath <uunet only>|
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