CITYFIBRE have acquired IT service provider Redcentric, adding 137km to a broadband infrastructure network that already spanned 1100km.
Incorporating Redcentric's pre-existing assets in Cambridge, Portsmouth and Southampton, CityFibre's broadband network now spans 40 metropolitan areas.
At least according to CityFibre themselves, this puts the provider on track to become "an increasingly powerful national competitor to BT Openreach".
However, even though they have been at the forefront of a handful of fibre optic trials involving BT's rivals, it's likely that CityFibre's potential as a major rival won't have a chance of being fully realised until after the uncertainty surrounding Openreach's "legal" separation from BT is resolved.
For the moment, CityFibre have to remain content with having laid down a network that's ready to connect some four million UK homes to an internet service provider (ISP).
This is already an impressive number, yet it pales in comparison to the 25 million premises actually serviced by the Openreach network.
In order to come anywhere near rivalling it, they'll have to continue doing what they've already been doing up until now, albeit faster.
They'll have to make more deals to supply their wholesale fibre network to such ISPs as Gigaclear, with whom they signed a deal in July. With their access ducts and fibre optic cables, the rural-focused Gigaclear expect to supply 100,000 homes with broadband connections of 100Mb or faster.
They'll also have to launch more collaborative projects like they did in York, where they teamed up with TalkTalk and Sky Broadband to bring speeds of 1Gb to 20,000 of the city's inhabitants.
This project has been claimed to have completed its first phase, having supplied 14,000 homes with fibre-to-the-home (FTTH) broadband.
Yet despite its relative success, and despite being a "trial" intended as a launchpad for other commercial undertakings, it hasn't been replicated anywhere else.
Added to this, CityFibre's partners in the project have recently shrunk away from conducting other ventures into their own broadband networks.
Normally, both TalkTalk and Sky offer customers an internet service based on BT's Openreach. However, TalkTalk had plans to use the CityFibre network and others to bring fast broadband to as many as 10 million homes.
Unfortunately, beyond the 14,000 customers in York, these plans haven't really progressed any further, not least because Sky have recently confirmed that they no longer have any intention to build their own, non-Openreach broadband network.
Without the involvement of a big player like Sky, TalkTalk lack the financial support and investment needed to bring their still hypothetical plans to fruition. By extension, so do CityFibre.
In other words, while their readiness to connect four million homes means that CityFibre have plenty of potential, they're suffering from a lack of interest.
Even though they're capable of supplying speeds of 1Gb, they're not attracting enough investment as it stands to mount a credible threat against BT's Openreach.
And perhaps the main reason for this resides with Openreach itself. Being owned by BT, and being used by every major ISP other than Virgin Media, it's too dominant at the moment to allow any rival network to gain a significant share of the market.
This is what most of the major ISPs appear to think, at least judging by their recent behaviour.
They seem to fear that, with more than 25 million customers, there's really no way a smaller emerging network could ever provide a genuine, cost-effective alternative to Openreach.
Not only would smaller rivals lack the economies of scale that 25 million connections can bring, but they would deprive ISPs of other advantages that come with using the long established network, such as the relatively lower cost of expansion.
This is one reason why some ISPs are holding off working with CityFibre as much as they could; another reason is simply that the current situation regarding Openreach's legal separation from BT has created uncertainty as to how the broadband market will develop in the future.
Even though this separation has been billed by Ofcom as promising to give Openreach independence from BT, rival ISPs believe that it will more or less preserve the status quo.
As Chris Bateman, the Chief Executive of the Federation of Communications Services, said when the separation was announced in June, "slapping a fresh coat of paint on the ship and rearranging the deckchairs won't help when the crew's all working to rule".
He and other critics of BT, including the campaigners behind Fix Britain's Internet, believe that a legal - not complete - separation will still allow BT to continue determining how Openreach's budget is spent.
As such, they suspect that BT will continue slowing down Openreach's investment in improved broadband, delaying upgrades to the network and further expansions of it into rural areas.
Observers might assume that this would be good for CityFibre, since the failure to enhance Openreach would make their network seem all the more attractive.
And yet, Ofcom's proposals surrounding legal separation have only created insecurity. While the details are being fully formulated, and even after the network has been legally separated from BT, rival ISPs will bide their time and see how the situation progresses.
As a result, they'll change nothing, holding off any major alterations in direction until a sense of the new Openreach is established.
For CityFibre, this has the result that some ISPs are reluctant to do business with them, in much the same way that some foreign business are withholding investment in the UK until after the dust has settled on Brexit.
Besides, the intense interest ISPs have in Openreach ultimately suggests they want to use it for themselves.
They want Openreach to split from BT precisely because they want more of a say in how Openreach allocates their resources and invests in new broadband.
And if this is what they want, then it's because the likes of Sky, TalkTalk and Vodafone want to continue using Openreach for the foreseeable future, albeit on better terms.
They therefore have no substantial interest in turning to a rival wholesale provider like CityFibre, which is why, even if CityFibre have shown considerable growth as of late, they won't ever become a serious threat to Openreach's dominance.
The only possible exception to such a scenario would be if the legal separation of Openreach and BT really didn't change anything in practice.
If Sky and TalkTalk continued being dissatisfied with Openreach's investment and continued, for instance, being overcharged by BT for essential maintenance work, then they might possibly consider turning to a seemingly more reliable competitor.
Yet as things stand, it may be a very long time before we receive a press release from CityFibre celebrating how they've overtaken BT as the UK's number one network provider.
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