METHOD AND APPARATUS FOR PLACING TEST CALLS IN A COMMUNICATION SYSTEM

• US 3,840,712 A
• Filed: 01/22/1973
• Issued: 10/08/1974
• Est. Priority Date: 01/22/1973
• Status: Expired due to Term

• Current Assignee: Eric Oberer, George William Riesz
• Original Assignee: Eric Oberer, George William Riesz
• Inventors: Oberer, Eric, Riesz, George William
• Primary Examiner(s): Claffy, Kathleen H.
• Assistant Examiner(s): Olms, Douglas W.
• Application Number:
  US05/325,608
• Time in Patent Office: 624 Days
• Field of Search: 179/175.2R,175.11,9R,9B 340/309.4
• US Class Current: 379/11
• CPC Class Codes: H04M 3/362 Traffic simulation
• CPC Class Codes: H04Q 3/00 Selecting arrangements H04Q5/00 - H04Q11/00 take precedence

Abstract

A method and apparatus for placing test calls to emulate traffic on a group of communication paths, such as a trunk group, or on a network in a communication system. Two series of sequential test calls are placed on test lines connected to a central office to seize circuits to a distant office. The test call sequences are timed so that one series of test calls holds a communication path for a period of time which at least partially overlaps with the period of time of individual calls of the other series of test calls. In the disclosed embodiment one-number dialers are employed together with an adjustable cam timer arrangement which seizes the test lines.

Claims

1. A method of emulating subscriber generated random traffic on a group of communication paths in a communication system comprising:

placing a first series of sequential calls wherein each completed call of the sequence is timed to hold one of said group of communication paths for a first period of time; and

placing a second series of sequential calls wherein each of the completed calls of the second series is timed to hold another one of said group of communication paths for a period of time that is at least partially concurrent with said first period of time whereby each call of the first series of calls competes with each call of the second series of calls for communication paths in the communication system.

2. A method of placing test calls on a group of communication paths interconnecting a plurality of end points in a communication system for accurately measuring the blocking experienced by actual customer traffic on said group of communication paths comprising:

placing a first series of sequential test calls between a first pair of end points with each completed test call holding one of said group of communication paths for a first period of time; and

placing a second series of sequential test calls between a second pair of end points with each completed test call of said second sequence holding one of said group of communication paths for a second period of time that partially overlaps said first period of time.

3. A method of placing test calls as recited in claim 2 wherein said first and second periods of time are approximately of equal duration and comprise approximately 0.36 of each test call time sequence;

and said second period of time overlaps said first period of time duRing approximately 0.72 of the first period of time.

4. A method of placing test calls according to claim 2 further comprising:

recording the number of test calls attempted during said first and second series of sequential test calls; and

recording the number of test calls completed during said first and second series of sequential test calls.

5. Apparatus for placing test calls to emulate traffic on a group of communication paths comprising:

timing means for generating first and second series of timing signals wherein each signal in said first series is time related to a respective signal in said second series;

first call placing means interconnected with said group of communication paths responsive to said first sequence of timing signals for placing a first series of sequential calls on said communication paths; and

second call placing means interconnected with said group of communication paths and responsive to said second sequence of timing signals for placing a second series of sequential calls on said communication paths whereby the period of time which said second call placing means holds a communication path during each call is at least partially concurrent with the period of time which said first call placing means holds another communication path during each call.

6. Apparatus according to claim 5 wherein said first and second call placing means comprise single number dialers.

7. Apparatus according to claim 5 further comprising:

first and second dial tone detectors interconnected between said first and second call placing means and said group of communication paths respectively and means responsive to said detectors for enabling said call placing means.

8. Apparatus according to claim 7 further comprising:

recording means interconnected with said first and second call placing means for recording the number of calls attempted and completed during each series of sequential calls.

9. Apparatus for placing test calls comprising:

rotating timing means;

first and second subscriber lines connected to a switching office;

first and second switching means connected in series with said first and second subscriber lines, respectively;

first dialing means interconnected with said first subscriber line;

second dialing means interconnected with said second subscriber line;

first dial tone detecting means interconnected with said first subscriber line and said first dialing means for activating said first dialing means when dial tone is detected on said first subscriber line;

second dial tone detecting means interconnected with said second subscriber line and said second dialing means for activating said second dialing means when dial tone is detected on said second subscriber line;

first cam assembly means for closing and opening said first switching means as said cam assembly rotates, said first cam assembly means having adjustable cams for holding said first switching means closed for a definite amount of time during each close-open switch cycle;

second cam assembly means for closing and opening said second switching means as said cam assembly rotates, said second cam assembly having adjustable cams for holding said second cam assembly having adjustable cams for holding said second switching means closed for a definite amount of time during each close-open switch cycle; and

adjustable rotating means for connecting said first and second cam assembly means to said rotating timing means for rotating each cam assembly means at different phases so that said first switching means will be closed during a period of time that partially overlaps the period of time said second switching means is closed.