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WikiProject Telecommunications (Rated C-class, Mid-importance)
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I'm trying to put together a reference to trunking in regards to ethernet networks, but I'm having a hard time figuring out how to integrate it into this article and not introduce confusion, since traditional circuit-switched telecommunications and packet-switched ethernet networking use terms like "switch" and "trunk" differently.

Ethernet port trunking likely best floating off on its own as a separate topic, with a reference to it on this page.

I'm not sure which trunking definition is more popular in terms of common usage. Certainly the circuit-switched definition is older, but it seems to be falling out of use in favor of packet-switched network terminology, as VoIP and broadband takes over as major telecomm services vs basic phone service. DMahalko 06:09, 08 june 2006 (UTC), Yahiya Hasan, Netsol

Trunk Line[edit]

Trunk line redirects here, but the article doesn't mention it. This is unfortunate. Harley peters 06:02, 14 November 2006 (UTC)


A T1 has 24 channels, each of which can carry a voice signal, or be combined to improve data bandwidth. ( With an IVAD ) Each channel is known as a trunk, while the T1 itself is a trunk group. Also, a DS3 is 28 T1s, and again, each individual channel would be a tunk, and each T1 would be a trunk group.

While VOIP may change this in future, its time has not yet arrived. Most telecommunications around the world, even in rich countries, is not performed using VOIP.

DigitalEnthusiast 20:47, 12 December 2006 (UTC)

Derivation Rework[edit]

The 'Derivation' section is utterly confusing. It is not at all clear whether the origins of the term come from the road, the railroad, the trunk of an elephant, or a tree trunk. If they are alternate and competing theories, this should be made clear. I take it that the origins of the term are unclear and the four options are just theories. Is this so? If I don't get a response to my comment, I will go ahead and modify the section to express this ambiguity rather than leave the reader wondering. Montblanc2000 21:37, 23 June 2007 (UTC)

Yes, please do. The mess is partly my fault. Jim.henderson 03:29, 24 June 2007 (UTC)

This article needs some attention, I think.

Radio Communication[edit]

This par hardly does the subject justice. Rather than expand it I think it should

be replaced by - See Trunked radio system


should be followed by a sub-heading - Trunk, to cover the next par. Additional definitions could be added here to cover some of the other usages of

the word.

Trunk Line[edit]

This par should be expanded to cover differences in usage over the last 100+ years, and between the two sides of the Atlantic.

Telephone Exchange[edit]

This heading should be changed to - Trunking. The reference to grading should be deleted or qualified, as there were/are plenty of trunking systems that didn't/don't use grading.


The elephant trunk theory is cute, but I think it's probably an urban myth. There are plenty of analogous usages - arteries, canals, roads, railways - all of which are derived from the tree/branch idea. I personally favour the railways analogy. UK practice tends towards 'trunk' (long distance) and 'junction' (local) lines, which could match up to railway usage, although 'main' and 'branch' lines are more common, these days, in that area. GusTheTheatreCat (talk) 10:15, 18 December 2007 (UTC)


Hey, I think that radio and telephone trunking is far more common than ethernet trunking. I'm going to change the order of the sections to reflect that, especially since telephones and radios have been doing it before the personal computer was even invented. I think even if you make a separate article, this one needs to have some reference to ethernet, but it shouldn't be the first case. --Kraftlos (talk) 18:39, 7 May 2008 (UTC)


Current text:


    "How the term came to apply to communications is unclear, ... "

This is not true The origins of railroad technology to describe the telephone network is clear. The railroad terminology came from Theodore Newton Vail. He had had a long relationship with Union Pacific when he became general manager of American Bell Telephone Company in 1878. The transcontinental railroad was largely finished by that time and there were all those railroad engineers (who knew networks and switching) looking for work.

They brought their terminology with them. To this day telephone company technicians refer to their call routing computers as "switches". — Preceding unsigned comment added by Axolotl23 (talkcontribs) 23:44, 31 January 2013 (UTC)

Good contribution. I added a linked mention of Vail, and I rewrote the section. I mentioned Vail more as a symptom than as a cause, because I believe it would be a Great-Man fallacy (Great Man theory > Criticism) to think that the model of usage wouldn't have suggested itself to everyone if a particular man hadn't "introduced" it. But your point is well taken, and thanks for helping to improve the section. — ¾-10 02:21, 1 February 2013 (UTC)
I've marked this whole section as needing a citation. has been in WP:MADEUP state since at least 2009. This is not a critical section for the article. If we can't find a citation, it is probably now time to delete it. -—Kvng 23:58, 3 February 2013 (UTC)
I've seen in one website, that took is based on a Northern Telecom training note, that the term came from

"the tracks that ran between two towns were called "Trunk Lines" because of the baggage (old sea trunks) that was carried over them"

Not a verifiable source, but warrants further research. Here's the website: Family Guy Guy (talk) 18:19, 22 May 2014 (UTC)

Deleted Etymology Speculation[edit]

I deleted this section. It was unreferenced since 2009 and was simply a couple of competing guesses. The elephant bit should have been nuked a long time ago. For posterity's sake the text was:

There are several apparent influences on the use of the "trunking" term in communication networks. The most elemental ones are the natural models of a tree trunk and its branches; tributary streams' confluence with rivers; and river deltas' branching of channels.

The term's previous use in railway track terminology (e.g., India's Grand Trunk Road, Canada's Grand Trunk Railway), which came from the natural models mentioned above, is another likely influence. Railway networks, with trunks, branches, and switches, were a contemporary model for many decades of the development of telegraph and telephone networks. In fact, turnover of employment among engineers in the railroading and telecommunications industries was not unusual during these decades, which makes the use of these analogies unsurprising. For example, Theodore Newton Vail had been a manager of railroad networks before he became an architect of telephone networks.

Another possible explanation is that, from an early stage in the development of telephony, the (up to around 10 cm diameter) containing many pairs of wires. These were usually sheathed in lead. Thus, both in colour and size they resembled an elephant's trunk. The elephant's-trunk hypothesis may be a false etymology.

--DouglasCalvert (talk) 20:37, 18 September 2015 (UTC)