Re: CS Fallback in NextEPC

Hi all,

I'd also like to test SMS and CSFB in LTE. I have some experience with the Osmocom GSM stack, but not much with the NextEPC LTE. Could you point me which fields should I set in the configuration files?

Thanks, Rafael Diniz

On 7/13/19 6:35 PM, Romeu Medeiros wrote:

Hello Sukchan and friends.

I'm trying to use the CSFB in test lab, and every time that nextepc send the UEContextModificationRequest, the UE respond with an UEContextModificationFaliure [ Protocol-cause=semantic-error ].

image.png

I'm looking why I'm getting this. Someone have any idea?

Thanks

Romeu Medeiros

On Thu, Jul 11, 2019 at 12:15 PM Sukchan Lee <acetcom@gmail.com mailto:acetcom@gmail.com> wrote:

Dear Osmocom & NextEPC Community,

Today I've added CS Fallback and released NextEPC v0.5.0

So, I'd just like to test this part with Osmocom project, but it
seems to be a difficult task. The reason is why I have little
knowledge about 2G/3G. Nevertheless, I will try to do it

BTW, I don't know if there is anyone who wants to integrate this big
thing.
Even though I'm not sure if this will help, but let me introduce the
configuration of the NextEPC.

To use SGsAP, change the mme.conf as follows:

#
#  <sgsap>
#
#  o Single MSC/VLR
#    sgsap:
#      addr: 127.0.0.2
#      plmn_id:
#        mcc: 001
#        mnc: 01
#      tac: 4130
#      lac: 43690
#
#  o Multiple MSC/VLR
#    sgsap:
#      - addr: 127.0.0.2
#        plmn_id:
#          mcc: 001
#          mnc: 01
#        tac: 4131
#        lac: 43692
#      - addr
#         - 127.0.0.3
#         - fe80::2%lo0
#        plmn_id:
#          mcc: 001
#          mnc: 01
#        tac: 4132
#        lac: 43692
#      - name: msc.open5gs.org <http://msc.open5gs.org>
#        plmn_id:
#          mcc: 001
#          mnc: 01
#        tac: 4133
#        lac: 43693
#

FYI, I also attach the pcap that I run with nextepc simulator as below.

$ ./tests/testcsfb
mo-idle-test        : SUCCESS
mt-idle-test        : SUCCESS
mo-active-test      : SUCCESS
mt-active-test      : SUCCESS
All tests passed.

Feel free to raise any questions about this things.

Best Regards,
    Sukchan