- This topic has 4 replies, 1 voice, and was last updated 21 years, 2 months ago by Gary Schultz.
11th January 2001 at 14:55 #33168Joseph BrewGuest
The Erlang tables uses the offered traffic to calulate the number of circuts and also the loss probability. since we can only measure the carried traffic how do we find the offred traffic?12th January 2001 at 03:45 #33169Richard ArcadiGuest
Joseph:May be it can help. For more than a decade I’ve been using the following relationship for peak hour traffic calculations.
It’s been certified by ITU and also by tons of real data provided by many telcos around the globe.
The simple equation goes as:
BHC = ASR * BHCA where
BHC: Busy Hour Calls :Switch OUTPUT
BHCA: BHC Attempts:INPUT at switch
ASR: Attempting Seizure Ratio (or the probability of getting al call through the switch).
Tipically ASR is between 60% to 80%. I use tipically 70%.
The calls stopped at the switch are grouped on 2/3 major factors:
1- B User Busy (about 8%-10%)
2- B User doesn’t answwer (same)
3- Network Congestion (the rest)
At Europe, Japan and USA ASR is above 80% for long distance and 85% for local calls.
The remaining countries average a 65%. This can be used with PABX.
firstname.lastname@example.org January 2001 at 14:29 #33170AlessandroGuest
Sorry, I remember that ASR is Answer seizure ratio and not Attempt seizure ratio.29th July 2001 at 11:38 #33171nourelhudaGuest
You mentioned you used 70%and user busy (about 8%-10%) is it the standards ?
– ASR 35% ?
– user busy 30% ?
– user not answer 35% ?
as we know the subscriber behaviou it can not be controlled .
for user busy can be solved by waiting call?6th August 2001 at 01:19 #33172Gary SchultzGuest
Offered traffic is a measurement that is normally obtained directly from the trunk group or line being examined.
In the DMS, offered traffic is called “incoming attempts” for trunks and “origination attempts” for lines.
These figures are referred to as “peg counts” – in actuality they are software registers peged by the call processing software whenever such an event occurs.
In the DMS, these registers are available from OM’s – Operational Measurements.
Every switch, whether it be Nortels DMS or Lucent’s 4/5e track the same information.