2021-02-11 11:35:33 +0000 commented answer Incoherence between ASN.1 and BER on gsm_map Anders, that was what I was missing. Well, everything is working fine. Thanks a lot, for real! have a great weekend! 2021-02-11 11:34:50 +0000 marked best answer Incoherence between ASN.1 and BER on gsm_map I need to decode a gsm_map protocol using tshark (under pyshark), specified as . Right now, I am able do decode everything up to "sai-Present". However, "eventInfo" gives the error "BER Error: This field lies beyond the end of the known sequence definition" and I'm not able to extract data inside, namely "CancelLocation". I've been told this happens because there is some incoherence between ASN.1 and BER. According to the specification, "eventInfo" (eventInfo [27] eventInfo OPTIONAL) should be encoded as Tag = 0xx9B Length = 0x01 Value = 0x0D -- cancelLocation  However, it is encoded as "9E 01 0D", as its specification was (eventInfo [30] eventInfo OPTIONAL). How can I fix this and make tshark able to decode the second encoding version of eventInfo? I'm running Tshark 2.2.4 on red hat 7.5. 2021-02-11 11:34:50 +0000 received badge ● Scholar (source) 2021-02-09 16:29:06 +0000 commented answer Incoherence between ASN.1 and BER on gsm_map Hi Anders, So, are you able to help me extend the gsm_map protocol to decode the proprietary fields? Thanks a lot for y 2021-02-06 16:41:52 +0000 commented answer Incoherence between ASN.1 and BER on gsm_map Hi. I'm on Red Hat Enterprise Linux 7. They're not standard compliant but it can be done, right? I'm sorry, this is an a 2021-02-05 17:28:42 +0000 commented answer Incoherence between ASN.1 and BER on gsm_map Hi Anders, sorry for the absence. So, I've been trying to follow what you told and the ws documentation to do this, but 2021-01-29 11:08:21 +0000 commented answer Incoherence between ASN.1 and BER on gsm_map Thanks for the answer! I can't seem to find that file on my install. Would you give me some hints on how to do that? i. 2021-01-29 10:46:01 +0000 received badge ● Editor (source) 2021-01-29 10:46:01 +0000 edited question Incoherence between ASN.1 and BER on gsm_map Incoherence between ASN.1 and BER on gsm_map I need to decode a gsm_map protocol using tshark (under pyshark), specified 2021-01-29 10:45:31 +0000 commented question Incoherence between ASN.1 and BER on gsm_map yeah, it was wrong. Thanks! 2021-01-28 19:24:20 +0000 asked a question Incoherence between ASN.1 and BER on gsm_map Incoherence between ASN.1 and BER on gsm_map I need to decode a gsm_map protocol using tshark (under pyshark), specified