19-09-2015, 01:52 PM
I'm in agreement with Brian here.
I think the confusion comes about because GPO terminology seems, largely, to have been confined in-house in the past, so that, in the outside world, people have used their own previous experience of plugs and sockets and applied it to the GPO terminology.
However, I don't think that all of these descriptions are that clear cut. Some years ago, an Indian colleague whose second language was English and whose technical knowledge was confined to his CATV experiences, joined a commissioning group responsible for the roll out of both CATV and Telephony.
Serge was confused by a discussion in which 'the Switch' was referred to several times so I leaned over and told him that 'the Switch' was what he would know as a Telephone Exchange. Our manager promptly rebuked me for using such an expression (!), saying that the Exchange is the building that houses the switch!
Unfortunately I wasn't quick enough of the mark to ask him what the 'X' in PBX and PABX stands for ...
When our VM phone died a couple of weeks ago, the engineer seemed to be getting some confusing readings outside and said he was going to the street cabinet so I told him that our line was on pair one and that it was also pair one at the cabinet up the road, which surprised him slightly until I told him that we'd had a problem before when an engineer had left his test phone jacked into our line!
After a bit more to-ing and fro-ing without a result he announced that he was going back to 'the Exchange'. Now apart from missing out a very important part of the network, the Switch is a mile and a half away and he certainly didn't have time to get there and back before he returned. Service was restored and he said there'd been a probem 'back at the Exchange'
So I asked him if he meant the Switch or the TDN* ...
* Cable telephony, like the CATV & Internet, is distributed to the local area over fibre, terminating respectfully at the CDN (CATV Distribution Node) or the TDN (Telephony Distribution Node).
The CATV signals are modulated onto the light as analogue signals and are easily recovered - the fibre receiver is usually integrated into the Launch Amplifier - but the telephony traffic is digital and requires a lot of intelligence in the street cabinet before final D/A conversion.
I think the confusion comes about because GPO terminology seems, largely, to have been confined in-house in the past, so that, in the outside world, people have used their own previous experience of plugs and sockets and applied it to the GPO terminology.
However, I don't think that all of these descriptions are that clear cut. Some years ago, an Indian colleague whose second language was English and whose technical knowledge was confined to his CATV experiences, joined a commissioning group responsible for the roll out of both CATV and Telephony.
Serge was confused by a discussion in which 'the Switch' was referred to several times so I leaned over and told him that 'the Switch' was what he would know as a Telephone Exchange. Our manager promptly rebuked me for using such an expression (!), saying that the Exchange is the building that houses the switch!
Unfortunately I wasn't quick enough of the mark to ask him what the 'X' in PBX and PABX stands for ...
When our VM phone died a couple of weeks ago, the engineer seemed to be getting some confusing readings outside and said he was going to the street cabinet so I told him that our line was on pair one and that it was also pair one at the cabinet up the road, which surprised him slightly until I told him that we'd had a problem before when an engineer had left his test phone jacked into our line!
After a bit more to-ing and fro-ing without a result he announced that he was going back to 'the Exchange'. Now apart from missing out a very important part of the network, the Switch is a mile and a half away and he certainly didn't have time to get there and back before he returned. Service was restored and he said there'd been a probem 'back at the Exchange'
So I asked him if he meant the Switch or the TDN* ...
* Cable telephony, like the CATV & Internet, is distributed to the local area over fibre, terminating respectfully at the CDN (CATV Distribution Node) or the TDN (Telephony Distribution Node).
The CATV signals are modulated onto the light as analogue signals and are easily recovered - the fibre receiver is usually integrated into the Launch Amplifier - but the telephony traffic is digital and requires a lot of intelligence in the street cabinet before final D/A conversion.
