by SlipperyDuck » Fri Nov 14, 2014 2:31 pm
Here is the rundown:
Two potential areas of congestion;
1. Telkom, your ADSL line provider - your line, plus your neighbors and others in the surrounding are all have lines that connect to an exchange where the ADSL cards live that turn your ADSL signal into DATA for the network. The Link/Lines between that exchange and core network is where you have your first potential problem with congestion. Normally telkom will add many more users than the capacity of that line between your exchange and the core network.
eg. 100 X 4Mb ADSL lines should add up to 400Mb needed for the Line between the Exchange and the core network. Typically however, there will only be 200Mb or even 100Mb there, based on return on investment and contention ratio calculations. --- This is without even considering Exchange path to core network where additional congestion points likely exist.
BOTTOM LINE: OVER SUBSCRIBED LOCAL EXCHANGE = ERRATIC HIGH PINGS AND POOR PERFORMANCE - BEFORE YOU HAVE EVEN USED YOUR ISP
2. ISP, your MB/month provider - Once your poor little bits have survived the journey across the ADSL and core network, they reach your ISP. At your ISP they have connections/lines at the Internet Exchanges in JHB/DBN and CPT, all via their OWN privately owned network. They also then have connections/Lines via the SAFE/SAT3/SEACOM/WACS paths out of South Africa to various Internet exchanges across the globe.
Congestion can be at the Internet Exchange points, the lines between cities and the Internationals.
Your ISP can have a certain IP Range (assigned when your ADSL Authenticates) use one set of Internation connections eg. SEACOM whilst others use SAT3, etc. This means that some users on say SAT3 international start experiencing slowness as their SAT3 cable is congested, is not felt by users who are on the SEACOM cable or the SAFE/WACS etc. Usually ISPs have more Bandwidth than their customer count, but not the guys that sell for Cheap (afrihost, webafrica, etc.)
BOTTOM LINE: POTENTIAL CONGESTION HAS MANY FACTORS HERE, GENERALLY YOU GET WHAT YOU PAY FOR - CHEAPER IS NOT BETTER IN SOUTH AFRICA AS CHEAP MEANS "OVERSUBSCRIBE ALL THE USERS"
Here is the rundown:
Two potential areas of congestion;
1. Telkom, your ADSL line provider - your line, plus your neighbors and others in the surrounding are all have lines that connect to an exchange where the ADSL cards live that turn your ADSL signal into DATA for the network. The Link/Lines between that exchange and core network is where you have your first potential problem with congestion. Normally telkom will add many more users than the capacity of that line between your exchange and the core network.
eg. 100 X 4Mb ADSL lines should add up to 400Mb needed for the Line between the Exchange and the core network. Typically however, there will only be 200Mb or even 100Mb there, based on return on investment and contention ratio calculations. --- This is without even considering Exchange path to core network where additional congestion points likely exist.
BOTTOM LINE: OVER SUBSCRIBED LOCAL EXCHANGE = ERRATIC HIGH PINGS AND POOR PERFORMANCE - BEFORE YOU HAVE EVEN USED YOUR ISP
2. ISP, your MB/month provider - Once your poor little bits have survived the journey across the ADSL and core network, they reach your ISP. At your ISP they have connections/lines at the Internet Exchanges in JHB/DBN and CPT, all via their OWN privately owned network. They also then have connections/Lines via the SAFE/SAT3/SEACOM/WACS paths out of South Africa to various Internet exchanges across the globe.
Congestion can be at the Internet Exchange points, the lines between cities and the Internationals.
Your ISP can have a certain IP Range (assigned when your ADSL Authenticates) use one set of Internation connections eg. SEACOM whilst others use SAT3, etc. This means that some users on say SAT3 international start experiencing slowness as their SAT3 cable is congested, is not felt by users who are on the SEACOM cable or the SAFE/WACS etc. Usually ISPs have more Bandwidth than their customer count, but not the guys that sell for Cheap (afrihost, webafrica, etc.)
BOTTOM LINE: POTENTIAL CONGESTION HAS MANY FACTORS HERE, GENERALLY YOU GET WHAT YOU PAY FOR - CHEAPER IS NOT BETTER IN SOUTH AFRICA AS CHEAP MEANS "OVERSUBSCRIBE ALL THE USERS"