ISDN lab?

malcybood

Okay, so I sit my 640-801 soon and am fairly confident with probably 85 - 90% of the material. Sure there are a few bits and bobs I need to brush up on but there is only one topic I have covered in little detail if any .....that's ISDN! .....I keep putting it off but not got much time to put it off any longer!

Does anyone have a suggestion on how to go about simulating an ISDN lab between two 1721 routers, to act as a backup link on DDR for say if there was a "fault" with my serial interface so communication could continue?

I have entered the ISDN commands into router simulators and the lab activities in the curriculum but I would ideally like to simulate this in my lab for peace of mind if anything and feel doing this will give me a better understanding.

I guess the first place to start is what type of cable required to link between the two routers crossover or straight or doesn't it matter?

I'm also a bit confused as to what the spid would be or would I just make one up?

Thanks

emsrescue

Hi Malc,

I have the same dilemma!

As far as i am aware the only way to setup ISDN have 2 routers with BRI intefaces and an ISDN simulator.

Jon

malcybood

Hi Jon,

Thanks for the info, that'll save me alot of time messing about trying to get them to work directly connected to each other then!

I just Googled an ISDN simulator and a 2 port simulator comes in at $649 apparently......yer' alright, I'll manage without it I think!

Thanks

Malc

redgoblin

I've got an ISDN simulator for alot less than that off ebay. They really shouldn't cost that much unless they're brand new (just get a used one). Have a look on ebay.

Ed Rooney

The isdn stuff in CCNA is pretty basic (ditto for frame-relay). I wouldn't waste money on it. Your sims should be for stuff you will do all of the time, like acl's, interface configuration and vlan configuration. $649 will get you a real router and a switch on craigs list.

redgoblin

I agree its not massively important, but for the cost of around £60 it doesn't cost alot and gives you hands on practise which helps to reinforce all the theory. I reckon its a good thing personally and should be done if possible.

If you work for an ISP (as I do) you might be dealing with ISDN on a day to day basis and would need to know it pretty well.

malcybood

Yeah well I am trying to get my foot in the door of an ISP so it would maybe be a sound investment.

What do you think about this?

http://cgi.ebay.co.uk/cisco-ccna-ccnp-lab-with-isdn-simulator-and-2-x-1603-r_W0QQitemZ120097320239QQcategoryZ69890QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Bear in mind it's actually £95 after postage and I've got 2 x 1721 routers with ISDN BRI cards.....should I just hang out for a simulator on it's own?

I've got 3 switches and 3 routers in my bedroom as it is without adding another 2 routers on top of this simulator!

On the same topic what about simulating ADSL? I've got some WIC ADSL cards also that I'd quite like to simulate?

emsrescue

Malc,

With anything thats designed to attach to the PSTN you really need a line simulator. So its the same with ADSL as ISDN.

If you really want to try it how about this: ebay isdn simulator or why not buy that kit on ebay and then sell a couple of the routers?

Jon

malcybood

Ahhh I got ya Jon, thanks

I'll have a think about the simulator you posted, maybe just wait and see how much it's at tomorrow night 10 seconds before the auction ends

Cheers

emsrescue

If you dont go down the line of simulating ADSL I could find a use for an adsl wic on my broadband connection

Jon

redgoblin

You'd probably be better off with a standalone ISDN sim - keep an eye on ebay as they have some from time to time. I probably wouldn't bother 'simulating' ADSL as its not really all that important. The only way it really differs from a normal Leased line is that way the data travels from the end user across the PSTN and towards the exchange (in England we use BT). From the exchange, I believe BT use L2TP tunnels to route the traffic to the ISP (and where the data is presented normally). If you follow what I'm saying, the only things you would actually be simulating are the way in which then end user data converts along the PSTN and travels through the L2TP tunnels which isn't really something that you'd wanna worry too much about and simulate!!. This doesn't apply to ISDN as it uses different technologies and is easily simulated.

Hope this helps!

malcybood

Thanks redgoblin that does help alot.

Cheers