Cellular Network Infrastructure » Core Network (CN) » OsmoSGSN

This field in current osmo-sgsn master (1d047ed24f71df635b973ac6e4541769531f1b8a) is printed as an empty string in CDR files or when showing it in VTY:

/* According to TS 03.60, Table 5: SGSN MM and PDP Contexts */
/* Extended by 3GPP TS 23.060, Table 6: SGSN MM and PDP Contexts */
struct sgsn_mm_ctx {
...
    /* the string representation of the current hlr */
    char             hlr[GSM_EXTENSION_LENGTH];
...

CDR output:

timestamp,imsi,imei,msisdn,cell_id,lac,hlr,event,pdp_duration,ggsn_addr,sgsn_addr,apni,eua_addr,vol_in,vol_out,charging_id
20171129095150346,901700000015254,357737055592090,555,0,5,,attach
20171129095154930,901700000015254,357737055592090,555,0,5,,pdp-act,0,127.0.0.2,127.0.0.1,internet,176.16.222.2,0,0,1
20171129095254930,901700000015254,357737055592090,555,0,5,,pdp-periodic,60,127.0.0.2,127.0.0.1,internet,176.16.222.2,22639,94088,1

Current config:

OsmoSGSN# show running-config

Current configuration:
!
!
log stderr
  logging filter all 1
  ...
!
stats interval 5
!
line vty
 no login
!
ns
 timer tns-block 3
 timer tns-block-retries 3
 timer tns-reset 3
 timer tns-reset-retries 3
 timer tns-test 30
 timer tns-alive 3
 timer tns-alive-retries 10
 encapsulation udp local-ip 192.168.30.1
 encapsulation udp local-port 23000
 encapsulation framerelay-gre enabled 0
bssgp
sgsn
 gtp local-ip 127.0.0.1
 ggsn 0 remote-ip 127.0.0.2
 ggsn 0 gtp-version 1
 gsup remote-ip 127.0.0.1
 gsup remote-port 4222
 auth-policy remote
 gsup oap-id 0
 ! apn * ggsn 0
 cdr filename /tmp/osmosgsn.cdr
 cdr interval 60
 timer t3312 600
 timer t3322 6
 timer t3350 6
 timer t3360 6
 timer t3370 6
 timer t3313 30
 timer t3314 44
 timer t3316 44
 timer t3385 8
 timer t3386 8
 timer t3395 8
 timer t3397 8
 no compression rfc1144
 no compression v42bis
end

VTY output:

OsmoSGSN# show mm-context all
MM Context for IMSI 901700000015254, IMEI 357737055592090, P-TMSI f8b8e560
  MSISDN: 555, TLLI: f8b8e560 HLR:
...

I'm not sure what's the content the HLR field should have, but probably not an empty string.