Can't remove last ISA member 1

[jasidija]

Hi - got handed a number from the telco that I need to IDC.
So, after adding the # to my IDC table and still not getting the correct treatment, I found that the route did not have that IDC table defined.
When I tried to add the IDC table to the RDB - I discovered I can't.
The Route Data Block is ISA. Apparently you can't have an IDC table associated with an ISA route. (?)
So... I figured I'd blow out the ISA route and rebuild it as a DID route.
(Not sure if there is any side effects to doing that - but that's another conversation)
Anyway - here's where I'm stuck: I go to remove all the members of the ISA route and I get this error:

SCH3179
Trunk(s) cannot be removed if the remaining number of trunks are less
than the sum of the minimum number of reserved trunks.

Ever seen that one before? I guess I need to nil the number of reserved trunks... So, where in the heck are 'reserved trunks' defined?

Thank you...

 

[StanleySteamer]

There will only be two side affects of removing the ISA route - no calls in and no calls out.

Your ISA route probably has a DID service route associated.
In the RDB look for SRVT. One of those should be the DID route that you want the IDC on. The service routes "share" the trunks in the ISA route.

 

[jasidija]

No calls in - I don't care... but it would suck if I couldn't call out to order pizza!
J/k - thanks Steamer.

So ISA is new to me. In this particular case, I think I am making the mental connection with what you're talking about (I was wondering why I had a DID route with no members - but I'll bet that's the associated service route you're referring to).

Okay... thanks for helping me figure out how to apply my IDC table.
But my first question still remains: let's say, for whatever reason, I really wanted to remove my ISA route. I would think the first thing to do would be to remove the members. I wasn't able to. Why is that? What is 'reserving' these trunks?

 

[jasidija]

And since we're on the subject of ISA...
What is the point of ISA?

I mean - if the Telco is handing me a PRI, couldn't I just configure a DID route data block and call it good?
Why do I have to build two route data blocks (ISA & DID service route) and deal with this 'sharing' business?
What is the benefit/use/purpose of ISA versus DID?

 

[StanleySteamer]

With the ISA master route you have a pool of trunks that can be managed by the customer to some extent.

Each service route can have a different minimum/maximum setting to ensure trunks are available for that service.

You might have an outgoing route for 911 calls with a min of 2 so that there will always be two channels "reserved" for emergency calls.

You could also control the max on an incoming route in a call center for example. So you could have different service routes for different incoming numbers and be able to throttle the number of calls by adjusting the max.

I think the minimum on any service route has to be at least 1 (minimum minimum) so if you really wanted remove the master route you would have to first out all the service routes.

 

[jasidija]

You nailed it. I found this under the ISDN gate opener of my DID route:
ISAR YES
RTN 10
MIN 1
MAX 23
Interesting... something so basic. I guess if I really wanted to remove the ISA route members, I'd have to first blow out the logical routes configured against the ISAR/Route Number.
I was going down that road - just to set up a simple DID IAO route - which, compared to ISA, is just a pass thru. But now I'm going to play around with the ISA and build me a couple other routes. I won't tell you how long I've been at PBX and never tripped over ISA. Crazy - still learning something every day.
Thank you, Sir Steamer!!!