[NCLUG] ISDN hardware and configuration

[Frank Whiteley]

----- Original Message -----
From: "Sean Reifschneider" <jafo-nclug at tummy.com>
To: <nclug at nclug.org>
Sent: Saturday, June 15, 2002 4:50 PM
Subject: Re: [NCLUG] ISDN hardware and configuration


> On Fri, Jun 14, 2002 at 08:28:17PM -0600, dobbster wrote:
> >I've never touched ISDN in my life, and I know virtually nothing about
> >it.  Apparently I have to learn, fast.  Do any of you have suggestions
>
> Use a router that will do the job for you.  They tend to work really well,
> though I think the NetGear has had some issues with doing NAT in the past.
> Sounds like Frank has a handle on that.
>
NAT should work fine.  Never seen a problem with it.  BTW, thanks again for
clueing 'bridging' help on that first lan/lan setup.  Worked great.

> You basically just have to set all the appropriate values in the router
for
> the phone numbers of each channel, configure NAT, dial-on-demand and
> bandwidth on demand, and off you go.
>
Correct switch selection also.

> The super nice thing is that ISDN connections usually take only a second
or
> two to make (unlike modem connections which take 30+ seconds).  As I
> understand your environment, ISDN with dial-on-demand (make a connection
> when a packet is trying to go out) plus bandwidth on demand (only dial one
> connection, unless we get a bunch of traffic, then bring up the second
> line) works really well and is much nicer on the ISP...
>
Yesss.  There are issues with some routers.  Bandwidth on demand plus
persistence and delay.  Most routers are set to default to some value in
seconds before they'll pull the second channel.  This is user configurable.
You can also configure persistence.  Generally 300 seconds, but this can be
changed.  You can also select 'always multilink' to force both channels.
Depending on the provider equipment, there may be some issues.  For Netgear
equipment running into PM3 hardware, there is a special command line
setting.  It's a known bug.  If not set, the second channel is iffy.

> >for cheap, reliable hardware?  We were thinking of just buying
> >something from eBay.
>
> You can't get cheaper than free.  I've got a Netgear ISDN router+4 port
> switch that you're welcome to have.  The only problem is that I don't know
> that I have a password for it.  If there's some way of doing password
> recovery, it should work fine for you...
>
If this is an RT348, I'd take Sean up on his offer.  You'll need to
re-initialize the router with Firstgear to erase the password and current
settings.  Firstgear is a Windoze GUI which is buggy but can be downloaded
from netgear.com.  The alternative is to flash the ROM with xmodem IIRC.
The instructions are on the Netgear site.

> >masqueraded network running through a modem that won't go above 33kbps
> >as a result of poor semi-rural phone lines.  It's a bit slow. :-)
>
> IDSL should have also been an option for you, the nice thing about that is
> you get a little extra speed (the signaling channel is used for data as
> well), and it's an "always on" connection.  It's basically just DSL ideas
> applied to ISDN.
>
> Sean

IDSL will do 144kbps in most cases.  May depend on CO facility.  Overall,
less expensive via third party providers (after setup), more expensive via
Qwest.  A real advantage is that most ISDN routers run half-duplex and most
IDSL routers run full-duplex, allowing lower latency.  Range is 35K feet
from the CO.  Often find an Adtran device attached to the house.

Frank Whiteley