Bug #3356
OsmoSGSN doesn't provide unique IDTAG_SERNR in IPA CCM
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Description
OsmoSGSN currently identifies itself simply as "SGSN" over the IPA/GSUP link to OsmoHLR.
This is wrong as it results in all OsmoSGSNs (in a multi-SGSN network) to register using the same identity, which in turn will render the HLR unable to store which SGSN is actually serving the subscriber, and/or to route messages accordingly.
It appears the change to "SGSN" was made in Change-Id: I0a60681ab4a4d73e26fe8f0637447db4b6fe6eb2 from "SGSN-00-00-00-00-00-00" before. Both the old and the new name are wrong though, as they're not unique.
The correct behavior AFAICT is "SGSN-" prefix with whatever unique identifier behind. We could make that suffix configurable in the VTY, if there's no other way to derive any other locally unique identifier. MAC addresses work fine for BTSs, but not for SGSNs: There might be any number of OsmoSGSNs running on the same physical / virtual machine with only one MAC address...
Related issues
History
#1 Updated by laforge over 2 years ago
- Related to Bug #3355: OsmoMSC doesn't provide unique IDTAG_SERNR in IPA CCM added
#2 Updated by laforge over 2 years ago
- Related to Bug #2796: OsmoHLR doesn't update VLR during UpdateLocation added
#3 Updated by laforge over 2 years ago
Note: The identifier must stay unique even across re-starts of the SGSN.
#4 Updated by stsp over 2 years ago
Would uuid_generate be a reasonable solution?
https://linux.die.net/man/3/uuid_generate
#5 Updated by neels over 2 years ago
stsp wrote:
Would uuid_generate be a reasonable solution?
https://linux.die.net/man/3/uuid_generate
The difficulty is to get the same UUID across program restarts, i.e. no random involved.
We should probably use an ID to be set in the config file (and loudly error-log if missing)?
#6 Updated by neels over 2 years ago
it would be good if the identification were at most 15 characters wide, so it fits in the HLR's sgsn_number.
#7 Updated by neels over 2 years ago
neels wrote:
it would be good if the identification were at most 15 characters wide, so it fits in the HLR's sgsn_number.
OK, turns out the GSUP clients are free to send pretty much anything they want (in the sense of arbitrary Global Title),
and osmo-hlr should be able to deal with that.
#8 Updated by neels about 2 years ago
- Related to Feature #3644: allow arbitrary bytes in Global Title (GT), a.k.a. the VLR,SGSN's identification towards the HLR added
#9 Updated by stsp about 2 years ago
- Status changed from New to In Progress
This has already been fixed in osmo-msc (see issue #3355). I'll prepare a corresponding patch for osmo-sgsn.
#10 Updated by stsp about 2 years ago
Proposed patch: https://gerrit.osmocom.org/c/osmo-sgsn/+/12243
#11 Updated by laforge almost 2 years ago
- Assignee changed from stsp to osmith
- Priority changed from High to Normal
