School of Specs IMS — the call as an internet sessionOverview

Where it stands, and how to follow it · chapter 6 of 7 · 7 minutes

6 Maintenance, and what is running now

Why 3509 of the 4939 documents are change requests, why one work item has been reopened in every release since Rel-7, and what sits on the table for Rel-19 and Rel-20.

6.1 What a mature subject's paperwork looks like

The local record holds 4939 IMS meeting documents [5]. Sorted by what kind of document each one is, the pile says plainly what this work spends its time on.

3509 of them are change requests [6]. A change request is the only way a published specification is ever altered: it names the document, the clause and the new words, and a group either agrees it or does not.

767 are pCRs [7] — proposed text for a study report, which is the same idea applied to homework that has not become a rule yet.

And the change requests are not spread evenly. 1680 of them name one single document, TS 24.229 [8], against 92 for TS 23.228 [9]. Which documents those are is What they write: the IMS family of specifications.

Beside a document the record often keeps one more word — what the meeting did with it. 1942 IMS documents carry revised [10] and 1736 agreed [11].

Then 379 approved [12], 297 postponed [13] and 189 withdrawn [14].

That word is about that piece of paper on that day. It never says the work behind it started, stopped or finished, and it never says why the room chose it.

6.2 One work item, reopened in every release since Rel-7

The clearest single example of that upkeep has a name: IMS Stage 3 IETF Protocol Alignment. Its stated area of work is keeping 3GPP's stage 3 IMS text aligned with the IETF — the body that writes the internet's own protocol documents [15].

It opened in Rel-7 under the acronym IMSProtoc, from the paper CP-060101 at meeting CP-31 IMSProtoc CP-060101. Every release since has carried a continuation of it, and the work plan gives each one its own acronym.

Acronym Release Documents
IMSProtoc IMSProtoc Rel-7 9
IMSProtoc2 IMSProtoc2 Rel-8 248
IMSProtoc3 IMSProtoc3 Rel-9 32
IMSProtoc4 IMSProtoc4 Rel-10 19
IMSProtoc5 IMSProtoc5 Rel-11 248
IMSProtoc6 IMSProtoc6 Rel-12 209
IMSProtoc7 IMSProtoc7 Rel-13 364
IMSProtoc8 IMSProtoc8 Rel-14 and Rel-15 169
IMSProtoc9 IMSProtoc9 Rel-15 123
IMSProtoc16 IMSProtoc16 Rel-16 72
IMSProtoc17 IMSProtoc17 Rel-17 26
IMSProtoc18 IMSProtoc18 Rel-18 45
IMSProtoc19 IMSProtoc19 Rel-19 62
IMSProtoc20-CT IMSProtoc20-CT Rel-20 19

The digit does not mean the same thing all the way down that table. IMSProtoc2 to IMSProtoc6 are titled "phase 2" to "phase 6"; from IMSProtoc7 on the title is plain "IMS Stage-3 IETF Protocol Alignment" with no phase in it.

And from IMSProtoc16 the digit is the release — 16 for Rel-16, 20 for Rel-20 — which it was not before: IMSProtoc8 covers Rel-14 and Rel-15 between them.

The largest of them is IMSProtoc7, with 364 documents behind it [16].

6.3 The reason has not been rewritten since Rel-8

The paper that opened the Rel-8 phase gives its justification in two sentences.

The paper that opened the Rel-20 phase gives the same two sentences, one word apart.

"Provides" became "provided". Nothing else in the opening moved IMSProtoc20-CT.

6.4 What is on the table now

Rel-19 carries 10 IMS rows in the work plan and Rel-20 carries 7 [17] [18]. A row is one group's share of one work item, so a handful of acronyms fills them.

Rel-19 was mostly about IMS falling over. FS_IMS_RES, the study, has 147 documents and CT4 behind it FS_IMS_RES, and the study report it wrote is TR 29.866 TR 29.866. Its own justification says why anybody bothered.

IMS_RES-CT is the work item that followed it, 101 documents across CT1, CT3 and CT4, specifying the solutions that study concluded on IMS_RES-CT [19].

Its row names sixteen documents it will change. Four of them this course has already met: the restoration procedures TS 23.380 TS 23.380 and the gateway interface TS 23.334 TS 23.334, both with IMS in their titles.

The other two are the SIP profile TS 24.229 TS 24.229 and the 5G core's subscriber-server services TS 29.562 TS 29.562, and neither of those has IMS anywhere in its name.

Rel-19 also put split rendering into IMS. SR_IMS is SA4's work, 84 documents, writing TS 26.567 SR_IMS TS 26.567.

It set out to identify the functional entities for IMS-based split rendering and map them onto the IMS architecture [20]. What the term itself means is not something this register explains.

6.5 Rel-20 has four things running and one marked deleted

FS_IMSResil carries on the resiliency work in CT4, 93 documents, writing TR 29.867 FS_IMSResil TR 29.867. The paper the work plan points at is CP-261069 CP-261069. Its reason is a loop:

FS_enIMS_ARC is SA2's architecture study, 51 documents, opened by SP-260686 FS_enIMS_ARC SP-260686.

It aims to introduce new capabilities in the IMS network for existing services and for the new service requirements identified for 6G, with every work task aimed at multi-vendor interoperable interfaces [21].

AIML_IMS-MED is SA4's media work, 32 documents, opened by SP-250878 AIML_IMS-MED SP-250878. It extends TS 26.114 TS 26.114 and TS 26.264 to carry AI and machine-learning data in IMS services [22].

The reason given is a market one: operators want real-time translation, speech to text and object detection inside a call [23].

IMSProtoc20-CT is the protocol alignment again, 19 documents, opened by CP-260044 CP-260044.

FS_IMSRE_SEC is the security side of resiliency, and it is the odd one. The work plan has "Deleted" written at the front of its own name. The same row also has an approved study paper, SP-251237, and 16 meeting documents against it FS_IMSRE_SEC SP-251237.

6.6 The percentage is not a status either

Each work plan row carries a completion figure the plan keeps by hand. IMSProtoc20-CT reads 25 per cent and FS_enIMS_ARC reads 12 per cent IMSProtoc20-CT FS_enIMS_ARC.

Read those as what somebody typed, not as a measurement. The register holds no field anywhere that says whether a piece of work is running, stopped or finished, and what it does and does not hold is Following it yourself, and what the record cannot tell you.

Where the numbers in this chapter come from

  1. why IMSProtoc2 was proposed the opening sentences of the justification of the work item description /var/www/whatthespec.net/data/data/wis/360029/CP-080794/CP-080794.md, copied word for word, read 2026-08-05. That file was taken as this work item's own because its name begins with CP-080794, the document the work plan points at
  2. why IMSProtoc20-CT was proposed the opening sentences of the justification of the work item description /var/www/whatthespec.net/data/data/wis/1110010/CP-260044/CP-260044.md, copied word for word, read 2026-08-05. That file was taken as this work item's own because it states the unique identifier of this work plan row
  3. why FS_IMS_RES was proposed the opening sentences of the justification of the work item description /var/www/whatthespec.net/data/data/wis/1010003/CP-232281-CP-232026/CP-232281-CP-232026.md, copied word for word, read 2026-08-05. That file was taken as this work item's own because it states the unique identifier of this work plan row
  4. why FS_IMSResil was proposed the opening sentences of the justification of the work item description /var/www/whatthespec.net/data/data/wis/1080002/CP-251280 was CP-251017/CP-251280 was CP-251017.md, copied word for word, read 2026-08-05. That file was taken as this work item's own because it states the unique identifier of this work plan row
  5. 4939 IMS meeting documents rows of table `tdoc` whose work item column holds, as a whole word, one of the 177 IMS acronyms — 159 different spellings of that column match, because it sometimes carries two work item names at once, asked of /var/www/whatthespec.net/data/database/api/api.sqlite on 2026-08-05
  6. 3509 IMS documents are of type CR IMS documents whose type column is exactly 'CR', asked of /var/www/whatthespec.net/data/database/api/api.sqlite on 2026-08-05
  7. 767 IMS documents are of type pCR IMS documents whose type column is exactly 'pCR', asked of /var/www/whatthespec.net/data/database/api/api.sqlite on 2026-08-05
  8. 1680 IMS documents name 24.229 as the document they change IMS documents whose change-request column names 24.229, asked of /var/www/whatthespec.net/data/database/api/api.sqlite on 2026-08-05, of which 1675 are of type CR, CR pack or draftCR
  9. 92 IMS documents name 23.228 as the document they change IMS documents whose change-request column names 23.228, asked of /var/www/whatthespec.net/data/database/api/api.sqlite on 2026-08-05, of which 92 are of type CR, CR pack or draftCR
  10. 1942 IMS documents carry the outcome word revised IMS documents whose status column is exactly 'revised', asked of /var/www/whatthespec.net/data/database/api/api.sqlite on 2026-08-05. The word is about that document and never about the work item
  11. 1736 IMS documents carry the outcome word agreed IMS documents whose status column is exactly 'agreed', asked of /var/www/whatthespec.net/data/database/api/api.sqlite on 2026-08-05. The word is about that document and never about the work item
  12. 379 IMS documents carry the outcome word approved IMS documents whose status column is exactly 'approved', asked of /var/www/whatthespec.net/data/database/api/api.sqlite on 2026-08-05. The word is about that document and never about the work item
  13. 297 IMS documents carry the outcome word postponed IMS documents whose status column is exactly 'postponed', asked of /var/www/whatthespec.net/data/database/api/api.sqlite on 2026-08-05. The word is about that document and never about the work item
  14. 189 IMS documents carry the outcome word withdrawn IMS documents whose status column is exactly 'withdrawn', asked of /var/www/whatthespec.net/data/database/api/api.sqlite on 2026-08-05. The word is about that document and never about the work item
  15. what IMSProtoc2 set out to do the opening sentences of the objective of the work item description /var/www/whatthespec.net/data/data/wis/360029/CP-080794/CP-080794.md, copied word for word, read 2026-08-05. That file was taken as this work item's own because its name begins with CP-080794, the document the work plan points at
  16. 364 documents carry the work item IMSProtoc7 rows of `tdoc` whose work item column names IMSProtoc7 as a whole word, asked of /var/www/whatthespec.net/data/database/api/api.sqlite on 2026-08-05; the first and last meeting are those of its earliest and latest upload stamp
  17. 10 IMS work plan rows are marked Rel-19 rows of table `item` in /var/www/whatthespec.net/data/database/api/wp.sqlite taken in by the acronym rule whose release field is exactly 'Rel-19', read 2026-08-05
  18. 7 IMS work plan rows are marked Rel-20 rows of table `item` in /var/www/whatthespec.net/data/database/api/wp.sqlite taken in by the acronym rule whose release field is exactly 'Rel-20', read 2026-08-05
  19. what IMS_RES-CT set out to do the opening sentences of the objective of the work item description /var/www/whatthespec.net/data/data/wis/1080001/CP-253168/CP-253168.md, copied word for word, read 2026-08-05. That file was taken as this work item's own because it states the unique identifier of this work plan row
  20. what SR_IMS set out to do the opening sentences of the objective of the work item description /var/www/whatthespec.net/data/data/wis/1030003/SP-240492 - revision of SP-240061 New WID on Split Rendering over IMS (SR_IMS)/SP-240492 - revision of SP-240061 New WID on Split Rendering over IMS (SR_IMS).md, copied word for word, read 2026-08-05. That file was taken as this work item's own because it states the unique identifier of this work plan row
  21. what FS_enIMS_ARC set out to do the opening sentences of the objective of the work item description /var/www/whatthespec.net/data/data/wis/1100026/SP-251692 was SP-251656 was of SP-251638 was SP-251411_S2-2511300_was_S2-2511257_New SID on IMS architecture enhancement r02/SP-251692 was SP-251656 was of SP-251638 was SP-251411_S2-2511300_was_S2-2511257_New SID on IMS architecture enhancement r02.md, copied word for word, read 2026-08-05. That file was taken as this work item's own because it states the unique identifier of this work plan row
  22. what AIML_IMS-MED set out to do the opening sentences of the objective of the work item description /var/www/whatthespec.net/data/data/wis/1080049/SP-250878_SP-250634/SP-250878_SP-250634.md, copied word for word, read 2026-08-05. That file was taken as this work item's own because it states the unique identifier of this work plan row
  23. why AIML_IMS-MED was proposed the opening sentences of the justification of the work item description /var/www/whatthespec.net/data/data/wis/1080049/SP-250878_SP-250634/SP-250878_SP-250634.md, copied word for word, read 2026-08-05. That file was taken as this work item's own because it states the unique identifier of this work plan row

Every source this course is built on

Check yourself

Answers appear when you pick one, with where they come from.

Q6.1 3509 of the 4939 IMS documents are change requests. What does that mix say about the work?

Q6.2 How often has the IETF protocol alignment work been reopened?

Q6.3 FS_IMSRE_SEC has the word Deleted written at the front of its own name. What else is true of it?

Q6.4 What did the Rel-19 resiliency study say it was for?

Q6.5 The Rel-8 and the Rel-20 phases of the protocol alignment open with the same justification. What changed between them?

This chapter was built from a source register generated 2026-08-05. A fresher build of the register may hold different numbers.