Identifying submarine links via traceroute

Wed Sep 29 13:45:23 UTC 2021

On 9/29/21 15:14, Dave Cohen wrote:

> As Mark says YMMV as different providers will have markedly different 
> conventions, however one additional challenge that will be widespread 
> is that most carriers are not placing their L2/3 hardware in the cable 
> landing stations, preferring instead to extend from the CLS to more 
> centralized POP locations via Layer 1. So what you will see between a 
> city pair like Tokyo-Seattle, which very obviously will require some 
> wet capacity, will actually be some combination of wet and 
> terrestrial. Between the terrestrial extensions and L2/3 overhead it 
> would be difficult to determine exactly what the underlying cable(s) 
> are even if you had a good idea of what the CLS to CLS latency was.

And with new cables being built (largely by the content folk), CLS-CLS 
termination is no longer in favour. New cables are now being extended 
into city data centres as an "informal" standard, because the content 
folk are not interested in dealing with CLS politics, especially for 
cables where they may collaborate with regular network operators, to 
some extent.

Even though the C2C cable stood for "city-to-city", it wasn't a true 
city to city cable. Some of the most recent cable builds (I'm talking in 
the last 1.5 - 2 years) have been the ones mandating SLTE's are deployed 
at carrier-neutral data centres, and not at the CLS. The CLS is just to 
house the PFE (power feeding equipment).

Mark.