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Community Member

FXS port hung on CME 2851 router.

Running CME 4.01 on 12.4(9) ipservices. I have an FXS port that cannot be shut down with shut/no shut. The light on the port stays on constantly. Also if you plug a POTS phone into the port all you get is a continuous fast beep. Included info on hung port below:

Thanks, in advance, Tony.

sh voice port summ:



============== == ============ ===== ==== ======== ======== ==

0/3/0 -- fxs-ls up up on-hook idle y

sh voice-port 0/3/0:

Foreign Exchange Station 0/3/0 Slot is 0, Sub-unit is 3, Port is 0

Type of VoicePort is FXS VIC2-2FXS

Operation State is UP

Administrative State is UP

No Interface Down Failure

Description is FAX Machine Main Building.

Noise Regeneration is enabled

Non Linear Processing is enabled

Non Linear Mute is disabled

Non Linear Threshold is -21 dB

Music On Hold Threshold is Set to -38 dBm

In Gain is Set to 0 dB

Out Attenuation is Set to 3 dB

Echo Cancellation is enabled

Echo Cancellation NLP mute is disabled

Echo Cancellation NLP threshold is -21 dB

Echo Cancel Coverage is set to 64 ms

Echo Cancel worst case ERL is set to 6 dB

Playout-delay Mode is set to adaptive

Playout-delay Nominal is set to 60 ms

Playout-delay Maximum is set to 250 ms

Playout-delay Minimum mode is set to default, value 40 ms

Playout-delay Fax is set to 300 ms

Connection Mode is plar

Connection Number is 51

Initial Time Out is set to 10 s

Interdigit Time Out is set to 10 s

Call Disconnect Time Out is set to 3 s

Supervisory Disconnect Time Out is set to 750 ms

Ringing Time Out is set to 180 s

Wait Release Time Out is set to 30 s

Companding Type is u-law

Region Tone is set for US

Analog Info Follows:

Currently processing none

Maintenance Mode Set to None (not in mtc mode)

Number of signaling protocol errors are 0

Impedance is set to 600r Ohm

Station name None, Station number None

Translation profile (Incoming):

Translation profile (Outgoing):

Voice card specific Info Follows:

Signal Type is loopStart

Ring Frequency is 25 Hz

Hook Status is On Hook

Ring Active Status is inactive

Ring Ground Status is inactive

Tip Ground Status is inactive

Digit Duration Timing is set to 100 ms

InterDigit Duration Timing is set to 100 ms

Hookflash-in Timing is set to max=1000 ms, min=150 ms

Hookflash-out Timing is set to 400 ms

No disconnect acknowledge

Ring Cadence is defined by CPTone Selection

Ring Cadence are [20 40] * 100 msec

Ringer Equivalence Number is set to 1

config of fxs 0/3/0:

voice-port 0/3/0

timeouts call-disconnect 3

connection plar 51

description FAX Machine Main Building.

Community Member

Re: FXS port hung on CME 2851 router.

what does your show voice call summ say? what happens when you reboot the router? Does it work then?


Cisco Employee

Re: FXS port hung on CME 2851 router.


Remove the connection plar from the voice port. See if this resolves the fast busy when the phone is taken off hook.

Community Member

Re: FXS port hung on CME 2851 router.

I found a bug in TAC Case collection:


It seems to be attributed to fax lines plugged into the FXS port, but the IOS code in question is different. I have had several "FXO disconnect " issues in the past and TAC recommended to use 12.3(11)T10, saying it was the most stable code for FXO / FXS VIC2 cards. You might try flashing to this IOS and see if it helps.

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