Talk:Signalling System No. 7

Number 7
I was a bit confused at first when I saw Signalling System #7 but I think that the # should be in the title, I can't find a referenced source at the moment as i'm about to go out. Let's agree here first what the title should be and then make the final change once and for all. ChrisUK (talk) 05:40, 12 May 2010 (UTC)


 * It is certainly not "Signaling System Number #7". Please desist from putting both the word "Number" and the "#" together in the lede. — Dgtsyb (talk) 07:31, 15 May 2010 (UTC)

Going to the ITU website and downloading some of the relevant specs (Q701,2 etc) theres no hash in the title - they use "No." as in Signalling System No. 7. Its possible the hash just slipped in as shorthand by engineers rather than being part of the original name. beardybloke (talk) 11:17, 12 May 2010 (UTC)
 * Sounds good enough to me. No # then seems like the way forward.  Should also remove the pound tag as well at the beginning.  To resolve the name completely, can you confirm whether the word 'number' included in the titles?  Is is Signaling System Number 7 or Signaling System 7?ChrisUK (talk) 21:43, 12 May 2010 (UTC)


 * All the ITU specs are free and online at www.itu.ch as PDF files, but in the main its neither, rather its "Signalling System No. 7" See this link as an example: I did look at a handful of others but not exhaustively beardybloke (talk) 13:23, 13 May 2010 (UTC)

Deployment scope
Where is the protocol not in use in the PTSN? Is it used internally for pulse-dialed and touchtone landlines after the local central office? Is it used by cell phone handsets? -- Beland (talk) 18:36, 26 July 2010 (UTC)


 * Apologies if I misunderstand your question, but its generally not in use around the edge of the network. where analogue signalling or other digital signalling systems are in use such as V5, GR303(? US V5 equivalent), similar proprietary systems or perhaps ISDN, etc are used more (or in the case of PBX singllaing then its DPNSS, DASS2, etc?) Its not in use on mobile handsets, though once it gets beyond the air interface it does become used by the upper layers of signalling employed by the handset? Its late and I'm giving up for the night but I'm sure someone else can be along to help you in more detail. beardybloke (talk) 23:12, 26 July 2010 (UTC)

I've been out of telecom for about 15 years, but even in the 1990's in Toronto, many businesses were switching from analog to digital trunks, particularly the T-1 variety (aka "Primary Rate Interface" or PRI) where they got 23 bearer channels and 1 signalling channel. If the customer CPE was up to date, that meant users could get calling line ID right to their extension on the PBX, DID trunks could use out-of-band signalling, etc. Granted most businesses in the world are small and use fewer than 10 telephone trunks (so don't need a PRI), but virtually every large business was changing out to PRI's. That's my experience; YMMV. 99.235.138.200 (talk) 14:58, 27 January 2015 (UTC)

F Links
The term F-Link, (and A-Link, B-Link etc), are not utilised in the ITU specifications and are not commonly known in Europe. The terminology in Europe relates to whether the link is directly connected to the SP or not. All signalling links directly connected to an SP are known as an Associated Signalling links, irrespective of whether they are connecting to an SEP, STP etc. —Preceding unsigned comment added by 192.91.191.29 (talk) 11:06, 27 January 2011 (UTC)


 * ITU-T Recommendation Q.700 Clause 2.3 identifies links attached to STP as quasi-associated and only links attached between SEP as associated. — Dgtsyb (talk) 06:44, 29 January 2011 (UTC)

Requested move

 * The following discussion is an archived discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section. 

The result of the move request was: page moved.   A rbitrarily 0   ( talk ) 23:34, 13 October 2011 (UTC)

Signaling System No 7 → Signalling System No. 7 – The name of the standard in ITU-T specifications ITU-T Recommendation Q.700 is the proposed title. Also, my hard copy of the American National Standards Institute ANSI T1.111-1992 has the proposed title, Signalling System No. 7. The current article title is simply wrong. — Dgtsyb (talk) 02:35, 5 October 2011 (UTC)
 * Comment: It is not "simply wrong" under Wikipedia's guidelines if a commonly-used name and spelling (see WP:COMMONNAME) like the American English spelling of "signaling" (see WP:ENGVAR) is preferred over an official name and spelling (see WP:OFFICIALNAMES). Zzyzx11 (talk) 04:45, 5 October 2011 (UTC)
 * Comment from the article, this appears to be more common in Europe than North America? So there seems like there should be an affinity towards British English, which would use the double-l, and as the official ANSI standard also uses the double-l, the double-l form would seem to be the better choice. 70.24.247.61 (talk) 05:02, 5 October 2011 (UTC)
 * Move. The title is capitalised, hence it should be treated as a proper noun. Since the official documentation of the standard uses the double-l, we should follow unless there's overwhelming evidence people are using this "Signaling System No 7" with the single-l as a proper noun. Deryck C. 08:38, 5 October 2011 (UTC)
 * Support as per comments above. Nageh (talk) 20:48, 5 October 2011 (UTC)
 * The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.

SS7 and "out-of-band"
I don't necessarily know if it's correct to say that SS7 uses "out-of-band" signaling, since that would be more like using the first 3500Hz for audio and then signaling in 3700Hz. I think it's more correct to say that SS7 uses common channel signaling, since bearer and control channels are distinctly separated in SS7. 63.211.239.34 (talk) 19:53, 28 February 2013 (UTC)
 * I agree with this point of view and it meshes with the older name, CCS7. Perhaps the "out of band" comes from a T1 system with 1 channel for signaling and 23 for transport.  — Preceding unsigned comment added by 71.176.201.187 (talk) 02:09, 7 March 2014 (UTC)
 * Out of band is a broad term. It not only applies strictly to frequency, but also distinct channels of transmission. Kbrose (talk) 15:30, 27 December 2016 (UTC)

Requested move 22 August 2018

 * The following is a closed discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. Editors desiring to contest the closing decision should consider a move review. No further edits should be made to this section. 

The result of the move request was: Contested move and consensus is not to move. Because of this the article was not moved. Dreamy Jazz 🎷 talk to me &#124; my contributions 14:14, 30 August 2018 (UTC)

Signalling System No. 7 → Signaling System No. 7 – The article is spelled wrong (one L in signaling). The move should occur to correct the spelling. Mblumber (talk) 16:02, 22 August 2018 (UTC)
 * This is a contested technical request (permalink). SarekOfVulcan (talk)  16:24, 22 August 2018 (UTC)

''18:34, October 13, 2011‎ Arbitrarily0 (talk | contribs | block)‎ m. . (18,860 bytes) (0)‎. . (moved Signaling System No 7 to Signalling System No. 7: requested move; consensus at Talk:Signalling System No. 7)
 * Contested because there are very reliable sources using the LL spelling. http://www.itu.int/rec/T-REC-Q.700-199303-I/en. I could be convinced to move it, though. See also previous RM above. -- SarekOfVulcan (talk) 16:24, 22 August 2018 (UTC)
 * This has been moved multiple times in the past. There is also an WP:RETAIN issue here that has been ignored several times. Conclusion: ugh. Dekimasu よ! 20:45, 23 August 2018 (UTC)

''04:32, June 26, 2011‎ Johnuniq (talk | contribs | block)‎ m. . (18,410 bytes) (0)‎. . (moved Signalling System No 7 to Signaling System No 7 over redirect: rv undiscussed move per WP:ENGVAR)

''03:05, June 25, 2011‎ Lincoln Josh (talk | contribs | block)‎ m. . (18,506 bytes) (0)‎. . (moved Signaling System No 7 to Signalling System No 7: I'm now doing total spelling check in the area. The British standard is widespread in Europe.)

''02:43, May 16, 2010‎ ChrisUK (talk | contribs | block)‎ m. . (19,029 bytes) (0)‎. . (moved Signaling System 7 to Signaling System No 7: This is correct title as per ITU standards - see talk)

''09:58, October 5, 2006‎ Gabi S. (talk | contribs | block)‎ m. . (9,690 bytes) (0)‎. . (moved Signalling System 7 to Signaling System 7: Spelling)''
 * Retain the current spelling with double 'L', per WP:RETAIN since it was the first spelling used by the creator way back in 2006, and also since being so doesn't mean it is incorrect,. It is just issue of English variant and perspective of editors/readers. Those who double their l's in everyday writing will see it as correct on first sight and those who know only American spelling/or advocate its supremacy will alway see this as incorrect or at least... less than correct. We can't even depend on "reliable sources" on this, because they also spell words based on such perspective. So I am sure NYT or American engineer will always spell it with single l, while the reverse is the case if you read  related content on UK's Guardian. Moreover, I think after these series of back and forth moves, it is right time to move-protect the page, because this will not stop in as much as British/American spelling  variation exists. –Ammarpad (talk) 21:21, 29 August 2018 (UTC)
 * Move protected as requested. Dekimasu よ! 23:04, 29 August 2018 (UTC)
 * That is good. Now people should focus more on improving the article. –Ammarpad (talk) 03:50, 30 August 2018 (UTC)


 * The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page or in a move review. No further edits should be made to this section.

Timeslots
In the physical network section, there are references to ‘timeslots’. The first of which links to an article on broadcast programming. Could someone clarify what that means in this context and potentially change that link? -  Chip &#x1f43a; • #TeamTrees&#x1F333; 19:09, 21 December 2019 (UTC)

Improved article?
Would it make sense to re-work a few of the technical aspects of this article along these lines? Chumpih (talk) 12:13, 20 January 2021 (UTC)


 * major functionality : description of each of these including:
 * discovery and directory
 * Call establishment
 * Routing and addressing
 * Architecture diagram + description of major components + their role
 * Talk through of how the protocol works for a few of the major functions


 * The article could certainly benefit from better structure, better technical and historical overview, and better detail. kbrose (talk) 20:06, 20 January 2021 (UTC)
 * If you haven't already done so, post a neutrally-worded notice on Wikipedia talk:WikiProject Telecommunications alerting readers of this discussion. Given the technical nature of this article, I have a hunch that such a notice 1) will be appreciated and 2) result in a better "end result." davidwr/  (talk)/(contribs)  20:10, 20 January 2021 (UTC)
 * Thanks for the suggestion. Done. Chumpih (talk) 00:36, 21 January 2021 (UTC)

Deprecation of SS7 in favour of VoLTE IMS and BGPv4 AS interconnect?
I mean, has not VoLTE and SMSoIP and ViLTE and RCS with E2EE going through Internet, like with normal interconnection (inter-) of autonomous systems (AS, -net) using BGP deprecated SS7? USSD over SGs and all other stuff is also available. Valery Zapolodov (talk) 17:48, 18 June 2021 (UTC)

"Signalling" or "Signaling"?
The title says Signalling with double L, but the article uses a single L. -- 185.176.78.206 (talk) 05:25, 16 November 2021 (UTC)
 * That's an WP:ENGVAR question. It looks like the current article text consistently uses American spelling. Signaling System No. 5 and Signaling System No. 6 titles use American spelling. Seems like a move to Signaling System No. 7 is appropriate and likely uncontroversial. ~Kvng (talk) 15:33, 16 November 2021 (UTC)
 * There is certainly a lot of history in spelling it with double-l, since that was the name primarily used around the world after the CCITT standardized it, a name that was used much less in the US, where the original publications called it Common Channel Interoffice Signaling. This is in contrast to the earlier systems, Signaling System 5 and 6. Most Bell System pubs spell 'signaling' (one el), but double-el can also be found. I think, I adjusted all these at one point to the most common historical spellings. kbrose (talk) 18:21, 16 November 2021 (UTC)
 * PS: A prior consensus discussion, see above, retains the original spelling. I think I agree with that. kbrose (talk) 18:26, 16 November 2021 (UTC)
 * Oops, I apparently willfully ignored the discussions above. If we're going with British English in the title, we probably should make the body text match that. I agree with 's conclusion: ugh. ~Kvng (talk) 01:15, 17 November 2021 (UTC)
 * I thought I already did that earlier. But some book titles decided otherwise, which I didn't change. kbrose (talk) 01:24, 17 November 2021 (UTC)
 * it appears you're content to use signalling in the proper noun Signalling System No. 7 (SS7) but use the American spelling, signaling, elsewhere. I would think we'd want to declare this a European topic and use British English throughout. ~Kvng (talk) 22:38, 20 November 2021 (UTC)
 * I don't think that is a good idea. SS7 is definitively an American/Bell System topic by origin, just like the other signaling systems. Proper names are always allowed to have any spelling, I would think. kbrose (talk) 01:56, 22 November 2021 (UTC)