I had a problem with my cisco 1750 router connecting to a Siemens PBX(E&M i/f). The problems are:
1) Calls from outside can reach the router and be routed to individual phones via the PBX(E&M), except that the connection time only lasts for a few minutes(1 ~ 5, quite random)
2) Cannot make outgoing calls.
Seems strange on why incoming calls are OK but cannot make outgoing calls at all, and the connection time only last for a while.. Does it matter with the router IOS version(I'm using c1700-sv3y-mz.121-3.T)? Also I wonder if I must ground the grounding screw(beside the AUX port on the back side) to the PBX's ground? Or can I do something to verify the router..?
If your calls are disconnecting after 3 min, you are not getting answer supervision. The signal ground for analog e&m ports is on pin 8 of the RJ-45 connector...it is best practice to make sure you have a common ground with the PBX for analog e&m applications. Here are some links that may help:
The problem was finally solved by "shorting" the router ground with the SG of individual voice ports on the E&M module. Really strange as router can only detect both on/off hook and send/receive digits after the hard-wiring.... But still need to check if this may have side-effects such as burning the line cards....
These are the paths to get to each CCX logs through CLI. They may be helpful if you are having issues accessing RTMT or downloading logs through it.
If you want to download them you have to prefix "file get " and you can add one of the options (re...