The hour during the specified day with the largest total usage, when summed over all trunk groups. Peak hour and busy hour are synonymous. With conventional traffic theory data analysis, there are two methods for determining the peak hour. One is the time-coincident peak hour, meaning that hourly usage values are averaged across days for each hour of the day. The other is the bouncing peak hour, meaning that the highest usage is selected for each day without regard to the average across days. For the bouncing peak hour the highest load on a given day may or may not occur during the time-coincident busy hour. These traffic reports and accompanying trunk group data worksheet only use the bouncing peak hour method. Note that if the total usage for the current hour equals the total usage for the previous peak hour, then the peak hour is the hour with the greatest number of total seizures.

Group Number. A number that identifies each trunk group associated with the displayed data. Group numbers are displayed in numerical order, beginning with the lowest administered number and continuing to the highest administered number.

Group Size. The number of administered trunks in the trunk group.

Group Type. The type of trunk in the trunk group. The system monitors/measures the following trunk types:

• Access Tie Trunk (Access)

• Advanced Private Line Termination (aplt)

• Central Office (co)

• Public Network Service Customer Provided Equipment (cpe)

• Direct Inward Dialing (did)

• Direct Inward/Outward Dialing (diod)

• Digital Multiplexed Interface Bit Oriented Signaling (dmi-bos)

• Foreign Exchange (fx)

• Integrated Services Digital Network (isdn-pri)

• Release Link Trunk (rlt)

• Session Initiated Protocol (sip)

• Tandem (tan)

• Tie Trunk (tie)

• Wide Area Telecommunications Service (wats)

Trunk Group Direction. Identifies whether the trunk group is incoming (inc), outgoing (out), or two-way (two).

Measurement Hour. The hour (using 24-hour clock) in which the measurements are taken. For the last-hour report, it is the last hour of measurement (each trunk group’s measurement hour is identical; but not necessarily the same as the indicated peak hour for the day). For the today-peak report, the measurement hour is the peak hour for each trunk group. Measurement hour for each trunk group can be different. For the yesterday-peak report, the measurement hour is the peak hour for each trunk group yesterday (each trunk group’s measurement hour can be different).

Total usage (in CCS) for all trunks in the trunk group. Represents the total time the trunks are busy (with calls) during the one-hour measurement period. Total usage measures each time a trunk is seized for use by an incoming call (whether it is picked up or not) or an out going call (only after digits have been dialed).

The number of incoming and outgoing seizures carried on the trunk group. This includes the number of times a trunk in the group is seized, including false starts, don’t answer, and busy.

Incoming Seize. The number of incoming seizures carried on the trunk group.

Group Overflow. The number of calls offered to a trunk group not carried or queued (if a queue is present). Calls rejected for authorization reasons are not included.

Trunk Group Queue Size. A number (0 to 100) that identifies the number of slots assigned to the trunk group queue. This number represents how many calls may be held in queue by the trunk group. If 0 is displayed, then no queue is administered. Hence, the other queue measurements are also 0. Generally, the queue size should be larger than the trunk group size; however, not more than three times as large as the trunk group size.

Calls Queued. The total number of calls that entered the trunk group queue after finding all trunks busy.

Queue Overflow. The total number of calls not queued because the queue is full. These calls receive a reorder signal.

Suggested actions: Generally, this field indicates the number 0. If this field indicates a high number, then either the queue size may be too small, or add more trunks to reduce the number of calls queuing.

Queue Abandoned. The number of calls removed from the queue in one of the following manners:

• By the system because they have been in the queue for more than 30 minutes

• By the user (for example, dialing the cancel code).

Suggested action: Typically, this field indicates a small number. However, a large number generally indicates the queue size is too large and people are abandoning because they remained in queue for a long holding time and gave up.

Out of Service. The number of trunks in the trunk group out of service (listed as maintenance busy) at the time data is collected. An individual trunk may be taken out of service by the switch whenever an excessive number of errors occur, or by maintenance personnel to run diagnostic tests.

Suggested action: If the trunks are removed from service by the switch, then the appropriate maintenance personnel should be notified. The objective is to keep all members of a trunk group in service. Generally, you should not make adjustments to the trunk group because of Out of Service trunks, but should get those trunks returned to service. For specific details, refer to Trunk Out of Service report.

Suggested actions:

• If the group direction is outgoing or two-way, then a high number in the % ATB field and nothing in the Grp Ovfl or Que Ovfl indicates everything is functioning normally. However, a more typical scenario is a high number in this field and a high number in the Grp Ovfl field. This indicates a possible problem that necessitates further analysis. Unless it is the last trunk group in the pattern, overflow is to the next choice trunk group, and the number in the Grp Ovfl field is of no great significance. Otherwise, the obvious choice is to add more trunks to the trunk group.

• If the group direction is incoming, then a high number in this field is bad. It indicates some incoming calls are probably blocked. Generally, you add more trunks. Therefore, % ATB and the number of calls blocked is low.

Percentage Outgoing Blocking. The percentage of offered calls not carried on the trunk group. It does not include unauthorized calls denied service on the trunk group (due to restrictions) or calls carried on the trunk group but do not successfully complete at the far end (that is, where there is no answer). For trunk groups without a queue, the calls not carried are those calls that arrive when all trunks are busy. The number of Outgoing Seizures is calculated as follows:

Similarly, the equation for calculating Outgoing Calls Offered is as follows:

For trunk groups with a queue, the calls not carried are those calls that arrive when all trunks are busy and the queue is full (Queue Overflow) and calls removed from queue before being carried (Queue Abandoned). For this scenario, the Percentage Outgoing Blocking is calculated as follows:

Suggested actions:

• You can increase the length of the queue rather than adding more trunks. Subsequently, you should monitor the Que Abd field to insure it stays within reasonable limits.

• If conditions are such that Step 1 is not appropriate, then you may find it necessary to add more trunks.

  Note:

  If you are using ARS you may see a high number in this field. This only indicates calls are overflowing to the next choice.

If the trunk group supports wideband (n X DS0) switching, the system displays a W next to the trunk group entry. In addition, if any trunk group on the report supports wideband switching, the system displays the tag W = Wideband Support in the report heading.