Can I 2

[sebgar]

Hi Specialists,

Apparently when I have two calls setup (both channels B being used), if I want to establish a third one, I need to wait for a free channel B. Can I force one call to hang up in order to liberate one channel B as I consider my third call more important?

Thanks a lot.

Cheers to All,

S

 

[ISDNman]

Not sure what you mean. You are correct that you are limited to 2 B channels and thereore can only have 2 simultaneous talk paths.

Of course "you" can hang up a line at any time. Presumably what you need to know if if your phone or software can do this automagically.

ANother point is that if your equipment supports this, you can get a feature called "additional call offering" which works pretty much like call waiting. In this case there would be only 2 talk paths simultaneously active, but you could have additional call(s) parked at the CO that could be retreived.

You need to discuss your needs with the manufacturer of your telephone or analog terminal adaptor. If they support what you need they can give you advice on what to request from the Telco to do what you want.

Best of luck

 

[sebgar]

Hi ISDNman,

Thanks a lot for your help.

Let me explain my situation a little bit more:

- I have an ISDN line at my business. One is for my backup and the other one for transmitting images if I get robbed in my shop.

- I also want to have an intrusion alarm connected in my shop, and I want it to have priority over the images information. But because I have only 2 ISDN B channels I was wondering if I could force the images information B channel to hang up in order the intrusion alarm to take over the channel B.

Thanks.

 

[ISDNman]

I guess this would be specific to the terminal adaptor used on the ISDN.

I guess this would be called something like "b channel" preemption"

If you are in the USA you own the TA and should contact them. If you are in another country you might be using a telco-provided TA of some kind and would need to ask them.

It is *possible* but you may or may not find a *practical* way to do it.

Good luck.

 

[KiscoKid]

On a Cisco device if you're using 2 channels like thisand a 3rd stream of data (which they refer to as interesting traffic) is generated, the router automatically begins a Fast Idle countdown (defaults to 20 seconds but you can reduce it if required).

This forces a B channel down if and only if it wasn't in use already by 'interesting traffic'. If the images already on the channel are non-interesting, this may be a way forward.

If the images are also interesting traffic, then admittedly I'm kind of unsure how you can configure what you want on an ISDN router save purchasing another ISDN2B connection from your comms provider.

 

[sebgar]

Hi ISDNman and KiscoKid,

Thanks a lot to both of you.

At the moment I am in Spain and asking Telefonica, they have informed that they don´t provide the "b channel preemption" service.

How much is a basic Cisco router allowing me to use the "Fast Idle countdown"?

Cheers,

 

[KiscoKid]

Cisco's entry-level ISDN devices are the 800 range (I've included a URL below). They're ideal for Small Office/Outlet setups with say up to 10 PC's.

There is 5 flavours of the 800 to choose from. Which one you prefer largely depends on which country you are in (U for America and S/T for Europe) and whether you want a built-in 4 port LAN hub

http://www.cisco.com/en/US/partner/...s380/products_data_sheet09186a008008872c.html

If you need any assistance choosing which is best, let me know.

 

[sebgar]

Thanks again KiscoKid