sundance-communications.com/forum Forums TDM Business Telephone Systems Inter-Tel Telephones & Systems Time Slots

I looked but couldn't find a good post on the time slot subject in relation to the inter-tel axxess system. Can anyone give me the low down or point me to a resource that better explains this subject?

I have two Axxess 9.x, 6 cabinet systems (different locations) . My cabinets are about full and I'm looking to bump into cabinets 7 and 8. I really need more T1 interfaces. I've heard that you are limited to 128 time slots per cabinet. I've seen lots of posts regarding how many time slots different cards take and I'm pretty comfortable with that info.

The story that I've heard that I can't seem to find any documenation on is that there are 16 time slots per card slot. Is that true regardless of what release of software you're running?

I have T1 cards in my existing cabinets that are right next door to each other (slot1, slot2) and have had it that way for over 4 years without any issues. My other system at 2nd location has an open slot next to each of the T1 cards (to the right).

If the open slot is a requirement (so the T1 can use 8 of the time slots of that open spot), does that limit you to 3 T1 cards per cabinet? Can you put a T1 card in Slot 7 and use all 24 channels?

My understanding is that you could put a 8 port card like a SLC8 in the slot next to the T1 and that would be OK, but nothing that would use more than 8 time slots.

Can someone please spell out this whole time slot thing for me.

Thanks.

The other guys will correct me if I'm wrong. This is how it has been explained to me. Think of Time Slots as concurrent licenses. You can load each cabinet to the gills. As an extreme example, 7 IPRCs w/daughter cards would be 224 devices in a single cabinet. The cabinet will only support 128 actively in use. The 129th device to go active, will not work. So the question is, if you go over the 128, what are the odds that the cabinet will need more at any given time?

If that is true, I'm in good shape. I try to keep the cabinets around 140 knowing that their is no way all of these devices are going to be 100% in use. Does the CPU count or take any time slots?

Thanks for the quick post!

All slots are allocated 16 time slots until you populate it with a card capable of over-subscribing the 16 (DKSC16, T1...). When you do that, all of those time slots go into a pool for dynamic distribution. In the programming software you can see the current allocation. Look under SYSTEM->CABINETS->RESOURCES and you'll see what I mean.

You have to read a bit between the lines though because a single DKSC16 will show it requires 32 time slots for non-blocking. This is because it assumes a theoretical config where each DKSC16 port has an SLA connected, thus using both logical circuits for a total of 32. Count your circuits and go from there. The 9.0 I&M manual has all of this explained on pages 2-17 & 2-18.

Also, in your ATM system, the ATM link to each sub-node has 256 time slots of which 224 are non-blocking.

Excellent Info - thank you.

Here is what one of my systems says today:

cab - Avail - Timeslots for NB
1 - 96 - 207
2 - 112 - 208
3 - 112 - 240
4 - 96 - 152
5 - 112 - 172
6 - 64 - 0

Cabinet 6 just has a few SLC cards.

I'm assuming the fact that I have available that is good.

The available column shows you what you can carry on that backplane, the non-blocking shows what you would need in the worst possible scenario. Remeber the software assumes full theoretical load to calculate the non-blocking value. Again, count up what you really have and subtract the available number. That's your real over-subscribing value.

FYI - If you had more station cards than trunk cards I wouldn't worry too much as it's impossible to queue calls without available trunks. If you have more trunks, then you would have a place to load up on calls and possibly approach blocking. Of course this is predicated on the the assumption you handle primarily inbound calls. Just don't forget you have two places for potential blocking: within each cabinet and on the ATM link.