On 2/12/06, Jim Cathey <[EMAIL PROTECTED]> wrote:
> I don't know telco terminology, but the phones are all in electrical
> _parallel_. The cabling is probably point-to-point as you say, not
> a star (hub) topology. _Every_ string of christmas lights I've
> ever seen is cabled point-to-point, though the electrical connections
> can be series or parallel depending on the bulb style.
>
> I like to distinguish between the electrical wiring and the cabling
> style, as they are different. Assuming they're not can lead to
> confusion.
I apologize, you are correct, the most common for phone wiring is Bus
topology, not Ring (which I was calling hub).
Bus Topology
In a bus topology, all jacks are on one cable that starts at the NID
and is routed through the house from one jack to the next and
terminates at the last desired jack location. All of the jacks (except
the last one, which is connected at the end of the cable) are
connected in the same manner as in a ring topology. This topology is
probably the most prevalent in existing homes that were pre-wired
during construction.
Bus Topology Advantages
Initial installation may use less cable than other topologies.
Easy to troubleshoot if wiring problems arise.
Little reason to be concerned about converting to a "hybrid" topology.
Bus topology provides no significant advantage over a "hybrid".
Attempting to extend from the "last" jack would probably require more
cable than changing to "hybrid".
Bus Topology Disadvantages
A cut or broken wire will cause loss of service at all jacks past the break.
Difficult to convert to three or more line installation.
Adding to existing installation almost always results in a "hybrid"
topology - see disadvantages of "hybrid".
Hybrid Topology
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