Local Exchange, Port, Port Server and Telephone Exchange

Forums › Spark New Zealand (including Skinny and BigPipe) › Local Exchange, Port, Port Server and Telephone Exchange

loafer

6 posts

Wannabe Geek

#76760 6-Feb-2011 13:24

I am getting really confused about the differences between the terms - local exchange, telehone exchange, DSLAM, port and port server. I have never found their definitions on the TCNZ website. If anyone could shed light on the terms and elucidate their differences, please.

Thank you,

Loafer

raytaylor

4014 posts

Uber Geek

Trusted

#435868 6-Feb-2011 13:48

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Telephone Exchange
These are scattered all around the country. They contain the telephone switching equipment that provides a dial tone and plain old telephone service on your loop. They range in size from a large 3 storey building down to a small shed in a farmers paddock.

Local Exchange
This is the telephone exchange that your house is connected to. Your Local exchange.
It is usually within 5km of your home.

DSLAM
Digital Service Line Access Multiplexer. This transmits the ADSL broadband signal down your telephone line. Your modem talks to this when it connects to the internet. The DSLAM is then connected into a national backbone of fibre optic links, and back to your ISP's head office usually in auckland.
The DSLAM usually sits in the telephone exchange building. Telecom have begun a cabnetisation program where they move the DSLAM closer to your home by placing them in roadside cabinets. This reduces your line or loop distance.
Your maximum broadband speed is usually set by the distance from your telephone exchange. In fact it is the distance to your DSLAM that you are connected to.

Port
A larger DSLAM has up to 192 ports. Each copper loop / line going out to a house or customers premesis needs to be plugged into a port to provide broadband service on the loop / line.
If you are told there are no more ports avaliable, this means that there are no dslams with avaliable ports in your local exchange or cabinet. When telecom have a waiting list of enough people, they will usually add another port card to a DSLAM.

Port Server
Dont know much about this. I would assume its just a DSLAM. Never heard the term before.

Ray Taylor

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loafer

6 posts

Wannabe Geek

#435892 6-Feb-2011 15:16

Thanks for the definitions, they are more comprehensible than the Telecom's glossary. I am interested in the way Telecom ADSL Availability Check Tool uses 'local exchange' and 'roadside cabinet' somewhat differentially. Any difference between these terms? Also, is the local exchange the green box that you see on the side of a street?

raytaylor

4014 posts

Uber Geek

Trusted

#435943 6-Feb-2011 17:51

It could be a green box on the side of the street, but usually its a big green box.
The broadband avaliablility checker will do two things

1) Take your phone number and see what line or copper loop is associated with it
2) Check telecoms records for the length of the loop between the associated DSLAM and the house

The DSLAM could be in a cabinet or it could be inside a local exchange building.

There are smaller green boxes or small cabinets that are all over the place but there is no active equipment in them. They are usually less a metre high and are just for copper patching.

Cabinets with DSLAM's in them look like these

Ray Taylor

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raytaylor

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#435948 6-Feb-2011 18:17

Ray Taylor

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loafer

6 posts

Wannabe Geek

#436068 6-Feb-2011 22:23

How, this is very visually explanatory! To run the risk of embarrassing myself, is local exchange exactly the same as local telephone exchange? I notice may small dark green cabinets with stickers that say 'High Voltage' in the streets of Auckland City and actually saw a cabinet as big as that only in Waitakere City.

raytaylor

4014 posts

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#436089 7-Feb-2011 00:05

High voltage ones would be power supply fuse boxes.
They disconnect your house power supply by removing the fuse in the street if you cancel your power supply.

Ray Taylor

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