Need definition of "Trunk Line" ?

Edwards Finance > Phones

Q. Could someone please give me an accurate definition of the phrase "Trunk Line" ?

A. A trunk is a connection between switches. In the PBX world, it is a connection to the outside from the PBX. In the central office world, it's a connection to another central office or to a toll network, as opposed to a subscriber. A line is a connection to a subscriber, or in the case of a PBX, to a station behind the PBX. So, if you have a PBX, your connections to the phone company are trunks, and you connection to phones behind the pbx are lines. In the strictest sense, there is no such thing as a "trunk line"; that is a contradiction in terms, in the telco sense. A trunk is a facility that is switched at both ends; a line is a facility that is switched at one end only. I.e., an interoffice "trunk" connects two COs and can be switched to any of several lines or even other trunks at either CO, hence it is switched at both ends. A "line" connects a subscriber (same as a customer) to a CO, where it can be switched to another line to a different subscriber or to a trunk to go to a different CO, hence the "line" is switched at one end only (the CO end). A PBX "trunk" is not a trunk in the telco sense, since it is switched at the CO end but always terminates at the same customer location. I.e., it looks and acts just like a POTS line, as far as the telco is concerned. However, from the subscriber's perspective, it *is* switched at the subscriber end (i.e., the PBX acts likes a small CO since many stations are switched among a few "trunks").

Ask Edwards a Finance Question

Other Questions:

Advice on Small Business Phone System ?

I have looked at Nortel CICS, but I don't think I can have the fax and digital answering machine on the system with out having an expensive analog card. I don't like the idea of a dedicated fax line. We are a small office and currently only ha...

"While many Americans agree it is bad manners if your cell phone rings during a movie, a Broadway play or a concert, should it be against the law, with offenders paying a $50 fine for each infraction? Politicians in New York City think so, an...

I am getting ready to change cell providers and would like to hear your opinions about various services and phones. I currently have a Motorola V60i with AT&T and am not very happy with the service or the phone. I plan on switching to Verizon...

I joined a phone company 3 month ago called international plus. After I got the bill from them, I found that all my local calls were charged as long distance and all my international calls were 4 times higher than I was told. I tried to call th...

The following is a typical response from the chumps at Microsoft. Before I return this piece of junk, can anyone give me any suggestions on how I might overcome these problems? I've read all the responses on this board concerning this phone a...

Edwards Finance Menu

Ask a Question
About Us / Me
Contact Me
Privacy Policy

Sitemap

My Favorite Sites

PFBlog
Google Finance
Yahoo Finance
Motley Fool
Nveille's Financial Blog
AllFinanceMatters
Free Money Finance
2MillionBlog
The Terror Finance blog

Q&A Subjects