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British Telecom Plans to Ditch POTS Network
Samurai Cat! writes "Yahoo news has a story up regarding British Telecom's plans to scrap their traditional circuit-switched telecom network in favor of an IP-based system." Their press release has more information.
posted like 3 days ago.
http://slashdot.org/article.pl?sid=04/06/09/190247 &mode=thread&tid=126&tid=137&tid=187&tid=2 15
Only 2 days ago!
what it doesn't mention in the summary at least is that BT are also moving to fiber in their new developments, especially in areas like around london; while the move from POTS won't directly affect users, the move to fiber will make the intarweb a whole fuckload faster for those who are lucky enough to get it.
unfortunately they will not be moving already laid lines to fiber for any time in the forseeable future.
make that clear, there is absolutely NO shortage of ipv4 addresses.
i just received the APNIC (asia pacific) address report for this week. here's a few fun numbers:
60% of the allocated ipv4 space has been allocated (yes you hear it right, 60%). that leaves us with 40% still to allocate. 40% of 32 bits. now:
2**32 = 4 294 967 296
4 294 967 296 * 0.4 = 1717986920
that's 1.7 billions address NOT ALLOCATED
but here's the kick, only 50% of that allocated 60% (30% of the total) are advertised (that means routable on the internet), which in turn mean much less than that are actually used (advertised does not mean it is in use)
>1. What are the odds of this actually being pulled off?
Its quite possible. Major long distance carriers already do this. There are some technical issues, but they can be addressed, and VoIP uses bandwidth way more efficiently than a circuit switched network, so long term, the cost benefits do appear to be there.
>2. How much will this effect me, a regular dialup and telephone user of British Telecom?
As a voice user, there may be initial problems with echo, garbled voice, and delay if BT doesn't do their homework. Those problems can usually be quickly alieviated in most cases by properly employing the QoS features typically provided by high end routers.
A bigger issue is high speed modem use over VoIP, particularly if low bitrate codecs are used. Its possible that they could effectively cripple dialup ISPs without affecting voice quality in any perceptable way.. I don't know how the british communications regulations work, but here in the US, telcos can (with very few exceptions) do whatever they want to the lines so long as voice quality isn't affected (although they do have to support 9600bps data rates, who wants to surf at that speed.) Hopefully, they will keep in mind modem users, but they may decide this is a good time to force customers into broadband.
VoIP isn't as exotic as people may think--you've been using it for several years on most long-distance calls for at least part of the circuit. And all of this traffic is H.323 and not SIP.
Telus, which operates local phone service in B.C. and Alberta and cell phone service nationwide, started switching over to VoIP last year and now carries most of long-distance callls between major cities over the Internet.
Actually, it's not 1.7 billion addresses. Because of the way the address space is allocated, not every potential address is available, and that's before you take into account things like CIDR (classless interdomain routing not this)
1. What are the odds of this actually being pulled off?
It shouldn't be that difficult. BT's telephone network is based on System X (and it's competitor System Y). The national network is completely digital. Each customer line would be analog (unless you have ISDN) until the local exchange, where the signal would be converted into 64 Kbits digital. Advances in technology allowed a single circuit board (A4 sized) to handle up to 4 customer lines, so the entire telephone exchange for a small village could be inside a shed. BT would probably start with upgrading the national network, then do a local exchange trial in London, and then roll out across the country.
2. How much will this effect me, a regular dialup and telephone user of British Telecom?
You probably wouldn't notice anything. For each exchange, they would do a gradual switch over. They'd start by adding the new links using IP packets, test them, then allow customer calls to use them, and finally disable the old system.
Vintage computer adverts: http://www.vintageadbrowser.com/computers-and-software-ads
That's the greatest promise of IPv6 - ISPs will no longer have to divide their customers over a couple of hundred individual address blocks spread over distant areas of the IPv4 space - it's kinda like running defrag over the address space, only that this time it won't become fragmented again after just a little extra use.
"here in the US, telcos can (with very few exceptions) do whatever they want to the lines so long as voice quality isn't affected"
Some comment about this, ETSI SS7 ISUP (it's probably similar in the U.S) has basically three bearer capabilities:
- Circuit switched data: bits exactly the same in both ends
- 3.1 Khz: spectrum quality in this band is not affected by transit and processing in the network.
- Speech: voice inteligibility guaranteed.
The central office asks for 3.1K when a POTS line calls and the network does it's best to guarantee 3.1K. However in very long distance calls it's not always possible, because of the echo cancellers and stuff. Faxes and modems send an echo canceler disable tone, but I ignore if this works always/sometimes/...
ISDN terminals can themselves ask for whatever they need, but the network can provide or refuse the capability depending on all the transit switches involved in the call being able to provide it.
Mobile phones always use Speech.
And about VoIP, I heard Lucent dropped it's softswitch project because it just didn't work. more info anyone?