E1 MFCR2 Implimentation Issues

Last week I was attempting to implement the 6th FreePBX server for my company, but the first with anything other than a standard T1/PRI circuit.

My connection in Mexico is an E1 with MFCR2, HDB3 and NCRC4. I am using a Sangoma A102 card, and have configured the MFCR2 settings as documented. The connection is delivered over a pair of coax cables, that go into a balun to convert the coax to standard RJ45. When I plug the circuit into the FreePBX box, the E1 goes green and I am able to make/receive about 50% of my calls. The link will get to the point to where no inbound calls will complete, and the success of the outbound calls drops to about 25%

Shortly after plugging the link in, I get the following errors at the AsteriskCLI (these were all taken at different times of testing, but are consistent behavior):

[2015-03-03 21:21:07] NOTICE[2287]: chan_dahdi.c:4590 dahdi_r2_on_line_blocked: Far end blocked on chan 17
[2015-03-03 21:21:07] NOTICE[2287]: chan_dahdi.c:4599 dahdi_r2_on_line_idle: Far end unblocked on chan 17
[2015-03-03 21:21:09] NOTICE[2291]: chan_dahdi.c:4590 dahdi_r2_on_line_blocked: Far end blocked on chan 21
[2015-03-03 21:21:09] NOTICE[2291]: chan_dahdi.c:4599 dahdi_r2_on_line_idle: Far end unblocked on chan 21
[2015-03-03 21:21:10] NOTICE[2287]: chan_dahdi.c:4590 dahdi_r2_on_line_blocked: Far end blocked on chan 17
[2015-03-03 21:21:10] NOTICE[2287]: chan_dahdi.c:4599 dahdi_r2_on_line_idle: Far end unblocked on chan 17
[2015-03-03 21:21:10] NOTICE[2287]: chan_dahdi.c:4590 dahdi_r2_on_line_blocked: Far end blocked on chan 17
[2015-03-03 21:21:10] NOTICE[2287]: chan_dahdi.c:4599 dahdi_r2_on_line_idle: Far end unblocked on chan 17
[2015-03-03 21:21:11] NOTICE[2287]: chan_dahdi.c:4590 dahdi_r2_on_line_blocked: Far end blocked on chan 17
[2015-03-03 21:21:11] NOTICE[2287]: chan_dahdi.c:4599 dahdi_r2_on_line_idle: Far end unblocked on chan 17
[2015-03-03 21:21:11] NOTICE[2295]: chan_dahdi.c:4590 dahdi_r2_on_line_blocked: Far end blocked on chan 25
[2015-03-03 21:21:11] NOTICE[2295]: chan_dahdi.c:4599 dahdi_r2_on_line_idle: Far end unblocked on chan 25
[2015-03-03 21:21:13] NOTICE[2295]: chan_dahdi.c:4590 dahdi_r2_on_line_blocked: Far end blocked on chan 25
[2015-03-03 21:21:13] NOTICE[2295]: chan_dahdi.c:4599 dahdi_r2_on_line_idle: Far end unblocked on chan 25
[2015-03-03 21:21:13] NOTICE[2295]: chan_dahdi.c:4590 dahdi_r2_on_line_blocked: Far end blocked on chan 25
[2015-03-03 21:21:13] NOTICE[2295]: chan_dahdi.c:4599 dahdi_r2_on_line_idle: Far end unblocked on chan 25
[2015-03-03 21:21:14] NOTICE[2291]: chan_dahdi.c:4590 dahdi_r2_on_line_blocked: Far end blocked on chan 21
[2015-03-03 21:21:14] NOTICE[2291]: chan_dahdi.c:4599 dahdi_r2_on_line_idle: Far end unblocked on chan 21
[2015-03-03 21:21:15] NOTICE[2281]: chan_dahdi.c:4590 dahdi_r2_on_line_blocked: Far end blocked on chan 10
[2015-03-03 21:21:15] NOTICE[2281]: chan_dahdi.c:4599 dahdi_r2_on_line_idle: Far end unblocked on chan 10
[2015-03-03 21:21:15] NOTICE[2281]: chan_dahdi.c:4590 dahdi_r2_on_line_blocked: Far end blocked on chan 10
[2015-03-03 21:21:15] NOTICE[2281]: chan_dahdi.c:4599 dahdi_r2_on_line_idle: Far end unblocked on chan 10

[2015-03-06 10:18:30] ERROR[33838][C-00000007]: chan_dahdi.c:4568 dahdi_r2_write_log: Chan 1 - Protocol error. Reason = Invalid CAS, R2 State = Answer Transmitted, MF state = MF Engine Off, MF Group = Backward Group B, CAS = 0x04
DNIS = 8131, ANI = 000, MF = 0x20
[2015-03-06 10:18:30] ERROR[33838][C-00000007]: chan_dahdi.c:4328 dahdi_r2_on_protocol_error: MFC/R2 protocol error on chan 1: Invalid CAS
== Spawn extension (ivr-1, s, 9) exited non-zero on ‘DAHDI/1-1’
– Executing [[email protected]:1] Hangup(“DAHDI/1-1”, “”) in new stack
== Spawn extension (ivr-1, h, 1) exited non-zero on ‘DAHDI/1-1’
– Hungup 'DAHDI/1-1’
New MFC/R2 call detected on chan 1.
[2015-03-06 10:23:53] ERROR[34262]: chan_dahdi.c:4568 dahdi_r2_write_log: Chan 1 - Protocol error. Reason = Invalid CAS, R2 State = Seize ACK Transmitted, MF state = DNIS Request Transmitted, MF Group = Backward Group A, CAS = 0x04
DNIS = 8, ANI = , MF = 0x38
[2015-03-06 10:23:53] ERROR[34262]: chan_dahdi.c:4328 dahdi_r2_on_protocol_error: MFC/R2 protocol error on chan 1: Invalid CAS
New MFC/R2 call detected on chan 1.
[2015-03-06 10:23:59] ERROR[34262]: chan_dahdi.c:4568 dahdi_r2_write_log: Chan 1 - Protocol error. Reason = Invalid CAS, R2 State = Seize ACK Transmitted, MF state = ANI Request Transmitted, MF Group = Backward Group C, CAS = 0x04
DNIS = 131, ANI = 000, MF = 0x30
[2015-03-06 10:23:59] ERROR[34262]: chan_dahdi.c:4328 dahdi_r2_on_protocol_error: MFC/R2 protocol error on chan 1: Invalid CAS
New MFC/R2 call detected on chan 1.

I have tried a new balun with no success.

The telco (Bestel) has been of little help. I believe there is a lot being lost in translation from English to Spanish.

I was able to work directly with Sangoma briefly before I had to leave and adjusted mfcr2_mfback_timeout and mfcr2_metering_pulse_timeout with no real change in behavior.

Does anyone have any suggestions on what to try, or what I may be doing wrong?

I’m having problems with Telmex, do you find a solution to your problem?