ADSL Performance Indicators
ADSL regulations as per Government Gazette no:29141
On 17 August 2006 the Authority's regulations on the provisioning of ADSL services was published in Government Gazette 29141 (Notice 1112 of 2006).
One of the regulations requires the presentation of key performance indicators comprising of at least Packet Losses, Average Latency and Jitter for the ADSL service as a commitment to good business practice which is illustrated in the documents on the right.
NB: the key performance indicators reported in these documents are for the ADSL service provided by Telkom, which Telkom describes as a best-effort service.
Understanding ADSL key performance indicator terminology
Contention Ratio: This is a measurement of the number of other subscribers you are “contending” with for your share of ADSL bandwidth leading to your local exchange. For example, a contention ratio of 20:1 means that you share your bandwidth with no more than 20 subscribers.
Deviation (Jitter): The variability over time of the packet latency across a network. See “Packet” and “Latency” below.
Lag: The extra time taken by a packet of data to travel from the source computer to the destination computer and back again. The lag may be caused by poor networking or by inefficient or excessive processing.
Latency: The time between initiating a request for data and the beginning of the actual data transfer. Packet: A packet is a unit of data that is routed between one place and another on the Internet. Besides the data itself, a data unit includes a source and destination address, an identification number and error-control information.
Packet loss: Data packets can arrive early, late, out of sequence, or never, resulting in slow downloads, choppy streaming video, etc. Packet loss is caused by high network latency and/or by network congestion due to heavy traffic.