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srsran / srsRAN_4G

Open source SDR 4G software suite from Software Radio Systems (SRS) https://docs.srsran.com/projects/4g
https://www.srsran.com
GNU Affero General Public License v3.0
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Incorrect decoding Full network name from EMM information message #480

Open trsvdev opened 4 years ago

trsvdev commented 4 years ago

Hello,

When connecting the UE to the EPC (open5gs), the Full network name is incorrectly accepted from the EMM information NAS message. When encoding the network name, EPC uses UCS2 as described by 3GPP TS 24.008 (clause 10.3.5.5a)

Does srsLTE support this Coding Scheme?

Thank you.

andrepuschmann commented 4 years ago

If it's wrong I'd say we don't support it. Can you provide logs and a PCAP with the messages in question?

trsvdev commented 4 years ago

Thanks for the quick reply.

I have already found that this is not supported. When learning, I use srsLTE as a library, and I do not have logs. In debugging, I found the _liblte_mme_unpack_network_nameie function and after executing _emm_info-> full_netname it contains: 0a 28 45 70 26 00 00 00 00 00 00 00 00 .... and should be: 00 45 00 55 00 52 00 45 00 43 00 4f 00 4d, the value is "EURECOM" Flag UCS2 in that function not process.

emm information_s1ap.zip

andrepuschmann commented 4 years ago

Thanks for the PCAP, we'll have a look at it.