tag:blogger.com,1999:blog-3993498847203183398.post4122123113929879685..comments2024-03-28T09:19:27.451+00:00Comments on RevK<sup>®</sup>'s ramblings: Pointless tests at BT MartleshamRevKhttp://www.blogger.com/profile/12369263214193333422noreply@blogger.comBlogger9125tag:blogger.com,1999:blog-3993498847203183398.post-55315392865606916502017-08-26T10:54:26.917+01:002017-08-26T10:54:26.917+01:00Seconded. Even if it doesn't survive a reboot....Seconded. Even if it doesn't survive a reboot. Thanks in advance.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3993498847203183398.post-9369998758594025232016-08-18T21:29:19.167+01:002016-08-18T21:29:19.167+01:00What code has to be run (via telnet i presume) to ...What code has to be run (via telnet i presume) to enable baby jumbo frames???i jenkhttps://www.blogger.com/profile/10610233257584914970noreply@blogger.comtag:blogger.com,1999:blog-3993498847203183398.post-26290225414078712652016-08-17T16:25:52.883+01:002016-08-17T16:25:52.883+01:00Maybe it is a simple typo, a missing Y! "The ...Maybe it is a simple typo, a missing Y! "The modem shall support ANY Ethernet frame size of between 68 and 1534 bytes" would make sense.wrshttps://www.blogger.com/profile/12425695265708850087noreply@blogger.comtag:blogger.com,1999:blog-3993498847203183398.post-67531186776491661342016-08-16T14:47:47.508+01:002016-08-16T14:47:47.508+01:00I have a friend who had ISDN in the mid 1990s. He ...I have a friend who had ISDN in the mid 1990s. He worked from home a lot and used it to run a VPN to work. This required the office to have an ISDN line as well, there was no ability to tunnel in via an ISP or anything like. At least both ends were on the same BT exchange so counted as a local call.Owen Smithhttps://www.blogger.com/profile/00890951742186614705noreply@blogger.comtag:blogger.com,1999:blog-3993498847203183398.post-4095400887206082662016-08-16T09:34:38.947+01:002016-08-16T09:34:38.947+01:00Same old story. Why did ISDN never take off here? ...Same old story. Why did ISDN never take off here? Because BT charged a premium for it (and kept on doing it into the 2000s because they had a warehouse full of kit to use up). In Germany in the 1990s you got ISDN unless you specifically requested analogue, same price, no messing.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3993498847203183398.post-39839219453909506312016-08-16T09:26:16.138+01:002016-08-16T09:26:16.138+01:00As you say the author's intention is clear (to...As you say the author's intention is clear (to anyone who understands how ethernet works).<br /><br />But the letter of the spec appears to say that as long as the device supports at least one frame size in the range 68 to 1534 inclusive, then it is a pass.<br /><br />So the tester's logic would be e.g. "my test shows that this modem supports a frame size of 526, and 68<=526<=1534, therefore I have shown that the modem supports a frame size between 68 and 1534, therefore the test passes".<br /><br />And by the same (silly) logic, changing 1536 to 1534 in the spec did change its meaning, because it means that a hypothetical device only capable of passing 1536-byte frames would now fail when it previously passed.mgboyeshttps://www.blogger.com/profile/11087136219633309258noreply@blogger.comtag:blogger.com,1999:blog-3993498847203183398.post-1024345690367451512016-08-16T08:27:52.237+01:002016-08-16T08:27:52.237+01:00Except that clearly the intention is to handle all...Except that clearly the intention is to handle all frames else the 1534 would not be part of the spec and the change notes would not say what it does.<br /><br />Anyway if it send AN Etherney frame of 1534 and it does not support it, it has failed, surely.RevKhttps://www.blogger.com/profile/12369263214193333422noreply@blogger.comtag:blogger.com,1999:blog-3993498847203183398.post-85691151336095497512016-08-15T22:42:33.608+01:002016-08-15T22:42:33.608+01:00Well it's obviously stupid, but equally you ca...Well it's obviously stupid, but equally you can see how the testers are simply testing to the letter of the (badly written) spec.<br /><br />SIN498 doesn't state "the modem shall support ALL ethernet frame sizes between 68 and 1534" it states "the modem shall support AN ethernet frame size between 68 and 1534". <br /><br />So as long as they can make at least one value from 68 to 1534 work then it's a pass.mgboyeshttps://www.blogger.com/profile/11087136219633309258noreply@blogger.comtag:blogger.com,1999:blog-3993498847203183398.post-70503132216180718552016-08-15T19:41:18.777+01:002016-08-15T19:41:18.777+01:00I would have liked to be surprised reading this, b...I would have liked to be surprised reading this, but sadly not. For a company that's still investing R&D money into fleecing an antique copper network when it would be better invested into fibre and national Wireless networks things like this just seen like the tip of the ice berg. For all the rhetoric about how we currently have most of the country getting faster speeds than xyz country etc I think in a few years we stand a good chance of being one of the slowest as others rapidly invest and deploy better choices of infrastructure. Numerous places around the world are now making gigabit internet an available option with prices that would compete with our current VDSL offerings and we struggle to get a minimum of 2Mbps without involvement from regulators. Shame on you BTebreyithttps://www.blogger.com/profile/00108579642499534695noreply@blogger.com