Scenario:
- Residential
- Two VOIP telephone lines served by two Cisco SPA-122
boxes - Each SPA-122 connects to separate Line 1 and Line 2 junctions
in the house basement - A single, 2-wire cable connects a wireless
telephone to Line 1 - A single, 4-wire cable connects a 2-line desk
telephone to Line 1 and Line 2
The problem:
Inbound calls on Line 2 will ring Line 1 once and display the CID on the wireless telephone during the CID cycle.
In other words, BOTH Line 1 and Line 2 ring and display CID on inbound calls to Line 2.
The Line 1 wireless telephone only rings once, even as the line continues to ring Line 2 on the desktop phone.
Tried:
Completely disconnecting the Line 1 SPA-122 from the circuit. Problem happens.
Completely disconnecting the desk telephone, down to disconnecting the wires from the wall jack. Problem happens.
Completely disconnecting the 4 wire cable that supplies the desk phone from the basement junction box. Problem does not happen.
Connected a new length of 4 wire cable to the junction box and tested with it still wound on the spool, leading no where. PROBLEM HAPPENS.
It's as if inbound calls on Line 2 are jumping / inducting cross-copper to Line 1 and ringing the wireless phone! Is this possible? How can it be fixed?
Best Answer
Is the 4 wire cable the type with 2 twisted pairs? If so, you may have the jacks wired incorrectly, such that the each telephone circuit is using 1 wire from twisted pair A, and one wire from twisted pair B. This would lead to increased and perhaps excessive electrical coupling from pair A to pair B.
If the 4-wire cable does not have 2 twisted pairs, then using a 2-twisted pair cable will reduce crosstalk between your two lines (provided you make sure that line 1 uses twisted pair A, and line 2 uses twisted pair B).