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Bug #3356

OsmoSGSN doesn't provide unique IDTAG_SERNR in IPA CCM

Added by laforge over 1 year ago. Updated 7 months ago.

Status:
In Progress
Priority:
Normal
Assignee:
Category:
GSUP interface
Target version:
-
Start date:
06/23/2018
Due date:
% Done:

0%

Spec Reference:

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

Related to OsmoMSC - Bug #3355: OsmoMSC doesn't provide unique IDTAG_SERNR in IPA CCMResolved06/23/2018

Related to OsmoHLR - Bug #2796: OsmoHLR doesn't update VLR during UpdateLocationIn Progress12/30/2017

Related to OsmoHLR - Feature #3644: allow arbitrary bytes in Global Title (GT), a.k.a. the VLR,SGSN's identification towards the HLRNew10/11/2018

History

#1 Updated by laforge over 1 year ago

  • Related to Bug #3355: OsmoMSC doesn't provide unique IDTAG_SERNR in IPA CCM added

#2 Updated by laforge over 1 year ago

  • Related to Bug #2796: OsmoHLR doesn't update VLR during UpdateLocation added

#3 Updated by laforge over 1 year ago

Note: The identifier must stay unique even across re-starts of the SGSN.

#4 Updated by stsp over 1 year ago

Would uuid_generate be a reasonable solution?
https://linux.die.net/man/3/uuid_generate

#5 Updated by neels about 1 year 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 about 1 year 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 about 1 year 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 12 months 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 11 months 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.

#11 Updated by laforge 7 months ago

  • Assignee changed from stsp to osmith
  • Priority changed from High to Normal

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