Sierra MC8775/ MC8775V connectivity problem on MikroTik


I’m using Sierra MC8775 and Sierra MC8775V to make an APN connection on my Mikrotik BaseBox 5.
My Sierra module specification is showed in follow

I install my MC8775 on the Mikrotik Router board and configure it as PPP connection.
My PPP connection works and I can see the Public IP of Sim Card. Unfortunately, My connection is not stable and it disconnect after a time.
The log file of the router board showed that MC8775 was trying to reconnect, but the connection could not initialized.

In Most of cases the modem doesn’t able to reconnect.
I checked the AT^SYSCONFIG and give the following result

which means

As the system mode is 14 which means it supports only WCDMA, I guessed It might be my problem.( because I’m not sure about Sim Card network coverge).
I changed the system mode 2 which means It selects the module mode automatically.
the above solution didn’t make my connection stable.
so I checked diagnostic information and dump crash files, the results are demonstrated in follow

00 F 03 Sleep ab 01806
01 F 01 URNTI is 01366
02 01 cmph 03855
03 01 ui_base 00610
04 29 rrccsp 23915
05 FF rr_gener 06789
06 93 dsumtspd 03922
07 29 gsdi_nv 00153
08 22 pbmgsdi 00571
09 22 mmgsdi_i 00555
10 28 cmals 00841
11 01 mmauth 03848
12 03 mmauth 04149
13 03 mmauth 04171
14 03 mmauth 04189
15 03 mmauth 04214
16 03 mmauth 04236
17 03 mmauth 04254
18 01 mmsim 00565
19 FF cmtask 00955

would you please tell me what does error code mean?
Or is anyone how can make my connection stable?

thank you in advance



The error codes are going to be internal addresses relating to the firmware mapping, this is not avaialble so uit is not a route to go down. also it will only be used when looking for an actual issue in the firmware.

You really need to establish whether the unit is actually attached to a network or not to do that you need to send the below command


This might be too new (as the unit you are using is ancient), in which case the below commands.


Between the ‘authenticated’ and the ‘terminating’ prompts can you exchange data? I am guessing not, so it may be your SIM does not have access rights.




Hi Matt

thank you for your kindly respond.
I checked all of AT commads which you told

at+creg? +CREG: 0,1,320A,334E

AT+CGREG? +CGREG: 0,1,320A,334E

AT+CSQ +CSQ: 25,99

AT+COPS? +COPS: 0,0,"",0

and would you please explain more about these sentences?

How can I check the above sentence?

what doest it mean ??? my Sim Cards are working with another modules like Huawei Mu709s ( actually I check it for some of my sim cards)

It’s necessary to notice that the sim cards have Private APN Name, So they will get static IP Addresses.

what do you think about Sierra modules frameworks version ?
should I update their frameworks ?

framework of MC 8775v is :

framework of mc 8775 is :

the last frame works which I found in net is :
and I downloaded from,2_MBit#Quellen




So the fact that the SIM card works on other units

The results below are conflicting. The GSTATUS command says you are packet switch attached on 3G but the CREG, CGREG commands say that you are attached to your home network and the COPS command says you are currently sat on 2G!

So just to clarify a few points.

  • You are using a SIM with a private APN which will allocate static IP addresses to the unit/SIM, based on what? Username and password?
  • What network/country are you operating in (given the unit thinks it is on its home network) and we cannot see the MCC/MNC from the COPS command?

Re the framework question I presume you are talking about the firmware running on the unit, problem is the unit is over 7 years old so finding the current firmware is a problem.

At present I am a bit lost as to what to suggest given the conflicting results and the mikrotik OS/board being a bit of an unknown to me?




Dear Matt
I appreciate your great help and I apologized because I made mistake in my previous message. It seems there were two different routerOS opened when I was writing my message.
the correct information of the modem is:

Current Time: 1051406 Temperature: 61
Bootup Time: 0 Mode: ONLINE
System mode: WCDMA PS state: Attached
WCDMA band: IMT2000 GSM band: Unknown
WCDMA channel: 10687 GSM channel: 65535

RX level (dBm):-78

+CREG: 0,1,5860,09339E90

+CGREG: 0,1,5860,09339E90

+CSQ: 9,99

+COPS: 0,0,"",2


yes, my SIM is working with private APN name and a static IP address will be allocated to SIM. I’m not so professional at this field, I only know there is no username and password. I simply add private APN name and my sim card will get the static IP address.



Ok so from what I can see from the responses below is that the unit is powered up and attached to the network correctly meaning it should be able to successfully perform a connection. After this it is all down to the mikrotik router OS of which I am no expert, I think you need to post on one of their forums to take it further.




thank you for your kindly responses,
would you please describe the parameter of the following pictures:
when the modem is working correctly
and when we lost our modem connection

please consider the above pictures are taken from two modem which one of them is working correctly and the another modem has lost the connection.
the parameters WCDMA L1 State and RRC State are different in the pictures.

to see what protocol is running in my MC8775, I checked !REL? command:
which parameters of this command are illustrated in following photo



I cannot be entirely sure but it looks like the network has forced the modem into a sleep mode. I do not know those layers or modes that intimately.