Because they are built in batches and take a long time to build so new equipment comes along. Even within batches there is a probability that later ships will include newer kit that will not be retrofitted until the earlier ships come up for refit. Ships from later batches can be radically different from earlier batches.
7 posts • joined 16 Apr 2018
It has been a few years since I retired so I don't know if carrier grade ethernet has actually appeared yet. I worked in transmission and one of the things that was very noticeable as ethernet bearers replaced TDM was the limited nature of ethernet fail over. We actually had situations were optical protection switchs were specified rather than end point protection because of their guaranteed 50ms switchover. This despite it introducing a single point of failure (the protection switch) and that ops only switch on loss of signal, not signal degrade which is standard in TDM. I suspect that the intermittent nature of ethernet compared to the continues nature of TDM will prevent the implementation of the type of protection schemes used in TDM environments. Unfortunately ethernet is cheaper and even when I retired we were providing customers with 100Gbs ethernet circuits. So far as I am aware the highest specified TDM client rate is 40Gbs and this is rarely implemented.
Having both Facebook and Twitter accounts my layman's impression is that Facebooks new privacy controls do not meet the requirements of GDPR and Twitter's does. Though I would have preferred that Twitter giving me a 3rd party processing yes / no option I would have like the option to choose who could and couldn't. Since the option was all or nothing I naturally chose nothing. I wait to see Facebook's next attempt to get valid consent
Not fit for purpose
When I was first exposed to IPv6 on a cisco course my immediate reaction was that it's use of MAC addresses to generate the IP address was a security risk. Since then although some of the issues with IPv6 have been addressed my opinion remains IPv6 was designed to address the issues of the time and these are not the issues of today. I agree that IPv4 will need replacing but like a number of the other respondents I think we need to develop a new scheme that is suited to modern needs and concerns.