Installing a router

how to connect a single WinNT machine to a 100MBit router for dial out

A new PC to be located at another place had just one serial port and this
one was thought for other hardware than a modem. As routers and modems are
similarly priced, I opted for a router. While the machine is being carried
around with the LAN setup as 100 Mbit, the router should also have a 100MBit
interface. Zyxel is currently the only one to have realized that. It is less
necessity than convenience, as resetting the LAN to 10MBit requires rebooting.

Zyxel Prestige 202

This is the device. It comes complete with manual, cables, powersupply.
The CD contains a 'PNC V1.23' software, which lets me do everything
thinkable with the router. Unfortunately, the manual refers to a different
software. The hotline (approx 1.5$ per minute) didn't know the software yet.


There is a straight and a crossover cable plus the ISDN cable. The crossover
cable comes between the PC and the router, as the straight cable would come
between a hub/switch and the router. The ISDN cable is connected to the ISDN
box provided by the telecom. And there is a plug type powersupply.

WinNT setup

The network setup (rightclick on network icon, properties, protocol, TCP/IP,
properties) requires the Default Gateway to be set to the IP adress of the
router. There are more properties to be set. Domain, DNS, ..Call your ISP
for details.The point is that all IP adresses outside your network are routed
to the ISP and its DNS respectively.
Routers require a different setup than modems. As routers are normally the
internet connection for larger companies, a router connection costs more
than a single user account. Somehow I was able convince the ISP, that there
is only one machine. They would notice anyway.

Get it running

That was the hard part. There are a great number of options. I was able to
loopback and ping the ISP from within the PNC software provided by Zyxel,
but not from the netscape or from the CMD window. After a few calls to the
costly hotline and to the ISP, the hotline told me : it is working with
our software, we don't care about other software or operating systems.
I gave up and called a network administrator of a company I know.
After 2 week I got it back, it was working. There was something wrong with
the IP adresses.
The configuration :
PPP as from the ISP - ask them
the network is   192.168.1.x  with subnet masks
the router is  with subnet mask
remote IP adress      with subnet mask
my WAN adress
Single User Account Yes
Telcosession idletimeout= ... call filtersets protocol 1
SUA server all 0 or
Filter 1 NetBIOS_WAN all Active
   1,2,3 Win95Netbios TCP/IP Broadcast drop
   4     UDP port number to 137 drop
   5     UDP port number to 138 drop
   6     UDP port number to 139 drop
Filter 2 NetBIOS_LAN Active 
   1     Custom TCP/IP Protocol 17 dest. IP adress&mask = port 53 = drop


A router is a great device when it works. Even the hang up timeout after idle
works, as it does not with modems under WinNT. With a modem it wasn't possible
to make an unattended download of more than 5 MByte, the modem would terminate
the call unless I would keep the browser busy (reading BYTE or whatever).
Now there is a settable idle timeout, and the router does it, not the PC.
Unfortunately limited network knowlege is not sufficient, when the hotline
is not having experts.


the choosen IP adresses 192.168.x.x, are reserved as private, a router won't
pass them, which works as a kind of firewall. On the other side, it is also
not possible to dial in from a remote site even if one wishes to do so.
Dial in (from the internet) requires valid IP adresses, which are given by
the ISP, a reason why such a setup costs more. The router would also support
dial in with various options

Important note to this device

Although it does not seem get warm when running, it should not be covered.
After having placed some papers on top, I noticed malfunctions, such as
not being reachable by the network. They were of thermal origin as the supplier


the following newsgroups are discussing problems :

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last updated: 14.feb.00

Copyright (99,2000) Ing.Büro R.Tschaggelar