Parameter: Channel Usage
The Channel Usage parameter is used to set a channel usage scheme for Network Access Points (NAPs), also called trunk groups, in order to avoid call collision.
This is also referred to as 'Line Hunting' or channel hunting. See http://en.wikipedia.org/wiki/Line_hunting
Values for this parameter are selected from a drop-down list in the NAP configuration page. The Channel Usage parameter can take on the followings:
ISDN and CAS NAP
| Channel Usage | Description |
|---|---|
| Round-Robin |
Traverse in order of all timeslots of the NAP, from first timeslot of first trunk to last timeslot of last trunk.
Note: the longest idle timeslot will be put in the head of the list and will be used prior to other timeslot. For instance, if timeslot 1 is idle for 10 minutes, and timeslot 2 is idle for 5 minutes, timeslot 1 will be used. So all timeshots will be averagely occupied in a long term base. |
| Lowest Timeslot |
Start from lowest timeslot of every trunk in the NAP and will reuse them when they are idle. The interval of reusing a circuit is 25% of all circuits of this NAP.
For instance, if you have 24 circuits in the NAP, and you make calls one by one, then it will use cic 1-2-3-4-5-6-1-2-3-4-5-6. There is also a 5s timeout to re-sort the idle timeslot list. Note: Lowest Timeslot algorithm is per-trunk. If multiple trunks in a NAP, the algorithm will try to use the available timeslot with lowest number among all trunks for the NAP. |
| Highest Timeslot |
Start from highest timeslot of every trunk in the NAP and will reuse them when they are idle. The interval of reusing a circuit is 25% of all circuits of this NAP.
For instance, if you have 24 circuits in the NAP, and you make calls one by one, then it will use cic 24-23-22-21-20-19-24-23-22-21-20-19. There is also a 5s timeout to re-sort the idle timeslot list. Note: Highest Timeslot algorithm is per-trunk. If multiple trunks in a NAP, the algorithm will try to use the available timeslot with highest number among all trunks for the NAP. |
| Lowest Mapping ID |
Start from lowest timeslot of first trunk, second lowest of first trunk, etc. Once the first trunk is full, will start using second trunk. Will reuse the channels if they are idle. |
| Highest Mapping ID |
Start from highest timeslot of last trunk, second highest of last trunk, etc. Once the last trunk is full, will start using second-to-last trun. Will reuse the channels if they are idle. |
SS7 ISUP NAP
| Channel Usage | Description |
|---|---|
| Round-Robin |
Traverse in order of all timeslots of the NAP, from first timeslot of first trunk to last timeslot of last trunk.
Note: the longest idle timeslot will be put in the head of the list and will be used prior to other timeslot. For instance, if timeslot 1 is idle for 10 minutes, and timeslot 2 is idle for 5 minutes, timeslot 1 will be used. So all timeshots will be averagely occupied in a long term base. |
| Lowest Timeslot |
Start from lowest timeslot of every trunk in the NAP and will reuse them when they are idle. The interval of reusing a circuit is 25% of all circuits of this NAP.
For instance, if you have 24 circuits in the NAP, and you make calls one by one, then it will use cic 1-2-3-4-5-6-1-2-3-4-5-6. There is also a 5s timeout to re-sort the idle timeslot list. Note: Lowest Timeslot algorithm is per-trunk. If multiple trunks in a NAP, the algorithm will try to use the available timeslot with lowest number among all trunks for the NAP. |
| Highest Timeslot |
Start from highest timeslot of every trunk in the NAP and will reuse them when they are idle. The interval of reusing a circuit is 25% of all circuits of this NAP.
For instance, if you have 24 circuits in the NAP, and you make calls one by one, then it will use cic 24-23-22-21-20-19-24-23-22-21-20-19. There is also a 5s timeout to re-sort the idle timeslot list. Note: Highest Timeslot algorithm is per-trunk. If multiple trunks in a NAP, the algorithm will try to use the available timeslot with highest number among all trunks for the NAP. |
| Lowest CIC |
Start from lowest CIC value of the NAP and will reuse them when they are idle. Similar to Lowest Timeslot, the interval of reusing a circuit is 25% of all circuits of this NAP.
Note: Lowest CIC is per-NAP. Timeslot with lowest CICs within a NAP will be used first (no matter on which trunk they are, only CIC is looked at in that mode) |
| Highest CIC |
Start from highest CIC value of the NAP and will reuse them when they are idle. Similar to Highest Timeslot, the interval of reusing a circuit is 25% of all circuits of this NAP.
Note: Highest CIC is per-NAP. Timeslot with highest CICs within a NAP will be used first (no matter on which trunk they are, only CIC is looked at in that mode) |
| Lowest Mapping ID |
Start from lowest timeslot of first trunk, second lowest of first trunk, etc. Once the first trunk is full, will start using second trunk. Will reuse the channels if they are idle. |
| Highest Mapping ID |
Start from highest timeslot of last trunk, second highest of last trunk, etc. Once the last trunk is full, will start using second-to-last trun. Will reuse the channels if they are idle. |
| Odd Lowest CIC |
Start from lowest CIC, odd value, and will reuse them if they are idle. Will only use even CICs when all odd CICs are used. |
| Odd Highest CIC |
Start from highest CIC, odd value, and will reuse them if they are idle. Will only use even CICs when all odd CICs are used. |
| Even Lowest CIC |
Start from lowest CIC, even value, and will reuse them if they are idle. Will only use even CICs when all even CICs are used. |
| Even Highest CIC |
Start from highest CIC, even value, and will reuse them if they are idle. Will only use even CICs when all odd CICs are used. |