Network Effectiveness Ratio

Network Effectiveness Ratio ( NER ) is a measure defined in the ITU-T recommendation E.425 for the quality of a telecommunications network . NER makes a statement about the probability with which a call attempt is correctly displayed at the destination. NER is calculated as the ratio of the number of displayed call attempts in the destination divided by the total number of call attempts made.

${\ displaystyle NER = {\ frac {{\ text {accepted calls}} + {\ text {busy cases}} + {\ text {free falls}} + {\ text {calls rejected by the device or by the subscriber}}} {\ text {total number of call attempts}}} \ cdot 100 \, \ mathrm {\%}}$

Usually the value is 99%.

NER must be distinguished from the more common measured variable ASR (Answer Seizure Ratio). The ASR makes a statement about the probability that a conversation will take place. ASR is calculated as the ratio of the number of calls divided by the total number of call attempts made. Usually the value is 70%. The difference is due to the behavior of the called party. If you do not answer or you are already on the phone, the call attempt was displayed correctly at the destination, but the call did not go through.

NER is always greater than ASR.

Individual evidence

↑ ITU-T Recommendation E.411: Quality of service, network management and traffic engineering - Network management - International network management. March 2000, p. 6.
↑ ITU-T Recommendation E.425: Network management - Checking the quality of the international telephone service - Internal automatic observations. March 2002, p. 3.

[1] ITU-T Recommendation E.411: Quality of service, network management and traffic engineering - Network management - International network management. March 2000, p. 6.

[2] ITU-T Recommendation E.425: Network management - Checking the quality of the international telephone service - Internal automatic observations. March 2002, p. 3.