 49528867Premium
join:2010-04-16
Fort Lauderdale, FL
kudos:3 | reply to batterup
Re: Running dedicated line for DSL said by batterup:In my day in New Jersey a T-1 would be put on copper only as a last resort; then it was two pair one for transmit and one for receive. In the building shielded cable had to be used for a T-1 DSL works on quad no problem.
Nowadays T-1's are run on a single unloaded copper pairs up to 12Kf and can tolerate up to 3Kf of bridged tap as long as the BT is not near the ends of the span.
Shielded or as it is more commonly known screened cable is no longer in vogue and rarely found in use outside of high powered trnasmitter/RADAR sites.
Wayne
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Certified Kwanon fanboy since 1971.  |
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 batterupI Can Not Tell A Lie.Premium
join:2003-02-06
Netcong, NJ | said by 49528867:Nowadays T-1's are run on a single unloaded copper pairs up to 12Kf and can tolerate up to 3Kf of bridged tap as long as the BT is not near the ends of the span. Shielded or as it is more commonly known screened cable is no longer in vogue and rarely found in use outside of high powered trnasmitter/RADAR sites. Wayne The laws of physics must have changed. DSL is an analog signal a T-1 is digital. DSL uses a a frequency a T-1 is 1s and 0s, off and on. |
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49528867Premium
join:2010-04-16
Fort Lauderdale, FL
kudos:3
1 edit | said by batterup:The laws of physics must have changed. DSL is an analog signal a T-1 is digital. DSL uses a a frequency a T-1 is 1s and 0s, off and on. That is incorrect while a DS1 signal is almost digital, over the copper a T1 and DSL pretty much utilize the same technologies.
Wayne
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Certified Kwanon fanboy since 1971. |
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 tschmidtPremium,MVM
join:2000-11-12
Milford, NH
kudos:8
 ·G4 Communications
·Fairpoint Commun..
 ·Hollis Hosting
1 edit | reply to batterup
said by batterup:The laws of physics must have changed. DSL is an analog signal a T-1 is digital. DSL uses a a frequency a T-1 is 1s and 0s, off and on. Original T1 was pretty crude, used simple bipolar signaling. T-1 was developed in late 50s, early 60s. At that time semiconductor technology was very limited. Even so digital carrier was a tremendous advantage over analog FDM. Simple on off signaling is spectrally inefficient, it required a dedicated pair in each direction and a cable could only support a limited number of digital circuits.
The advent of cheap large-scale integration means complex modulation schemes could be used. Current generation T-1 makes extensive use of DSP, much like DSL. It is more spectrally efficient, which is why modern T-1 only needs a single pair.
FCC regulations require Telcos to deliver T-1 over traditional two pair interface. However how signal is transported from customer to CO is not specified.
/tom |
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49528867Premium
join:2010-04-16
Fort Lauderdale, FL
kudos:3 | said by tschmidt:FCC regulations require Telcos to deliver T-1 over traditional two pair interface. However how signal is transported from customer to CO is not specified. /tom Telco's do not hand off a T1 to the customer, the T in T1 implies transport, what is handed off to the customer is a two pair or four wire DS1 (digital signal level 1).
Wayne
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Certified Kwanon fanboy since 1971. |
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tschmidtPremium,MVM
join:2000-11-12
Milford, NH
kudos:8 Reviews:
·G4 Communications
·Fairpoint Commun..
·Hollis Hosting
| said by 49528867:Telco's do not hand off a T1 to the customer, I understand that and you are correct. But it is common usage to call a 1.544mbps connection a T-1.
/tom |
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 Killa200Premium
join:2005-12-02
Southeast TN
 ·Charter
| reply to dmxrob6
Hell a lot of the T1 work around here is done over single pair xDSL (added the x as i can't remember what spec they run to do this) terminated into a smart card on side then broke down into the t1 ATM circuit for a good 5 feet or less into the router.
That always killed me thing about it, because this solution cuts down on the telco's costs of delivery by using 50% less copper, and the transport equipment has to be cheaper than the old stuff. Yet around here we still get charged ~$900 for a full t1 circuit that is about as stable as dsl due to OSP issues the telco just isn't going to fix. |
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 nunyaWho is John Galt?Premium,MVM
join:2000-12-23
O Fallon, MO
kudos:8 | Most new T1's in AT&T land are HDSL2 on Adtran doublers (if needed). If it's RT fed, then whatever cards fits. |
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| reply to batterup
said by batterup:The laws of physics must have changed. DSL is an analog signal a T-1 is digital. DSL uses a a frequency a T-1 is 1s and 0s, off and on. WOW !!! I see a major class action law suite here. DSL (Digital Subscriber Line) is analog ?? Must be all kinds of false advertising and misrepresentation claims just waiting to be filed. Excuse me while I find a lawyer.  |
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49528867Premium
join:2010-04-16
Fort Lauderdale, FL
kudos:3 | reply to nunya
said by nunya:Most new T1's in AT&T land are HDSL2 on Adtran doublers (if needed). If it's RT fed, then whatever cards fits. Adtran HDSL2 is a non-doubled single pair 186 volt tip to ring span powered system utilizing a H2TUC at the CO or RT and a H2TUR/Smartjack at the prem with a practical reach of 12Kf on 24 ga.
Adtran HDSL4 is an extended reach two pair 186 volt across T/R and T1/R1 span powered system utilizing a H4TUC at the co or RT and a H4TUR/Smartajck with a practical reach of 14Kf on 24 ga which can be doubled three times.
Wayne
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Certified Kwanon fanboy since 1971. |
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49528867Premium
join:2010-04-16
Fort Lauderdale, FL
kudos:3 | reply to Waterbug
said by Waterbug:WOW !!! I see a major class action law suite here. DSL (Digital Subscriber Line) is analog ?? Must be all kinds of false advertising and misrepresentation claims just waiting to be filed. Excuse me while I find a lawyer. Hows that?
Wayne
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Certified Kwanon fanboy since 1971. |
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| said by 49528867:said by Waterbug:WOW !!! I see a major class action law suite here. DSL (Digital Subscriber Line) is analog ?? Must be all kinds of false advertising and misrepresentation claims just waiting to be filed. Excuse me while I find a lawyer. Hows that? Wayne As stated in his post, batterup said that DSL is analog. If it is analog than Digital Subscriber Line (DSL) is a misrepresentation of the product. MFMSL (Modified Frequency Modulation Subscriber Line) would be a more appropriate name. |
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1 edit | But it gives you a nice digital signal out of the Ethernet port of the DSL modem. |
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tschmidtPremium,MVM
join:2000-11-12
Milford, NH
kudos:8 Reviews:
·G4 Communications
·Fairpoint Commun..
·Hollis Hosting
| reply to Waterbug
said by Waterbug:If it is analog than Digital Subscriber Line (DSL) is a misrepresentation of the product. Getting really off topic but I'll chime in. The macro world is analog except when one gets down to the Quantum level.
Modern communication systems make extensive use of DSPs to implement complex modulation schemes. So the notion that digital means simple on/off signally is no longer accurate.
A better description of analog vs digital is that analog may assume any arbitrary value between minimum and maximum extremes. Digital signaling is limited to a finite number of discrete values. That number may be very large, as in the case of discrete multi tone (DMT) modulation, used by ADSL. But it is nevertheless a discrete number of permissible values.
This is why digital transmission can be lossless. There are a relatively small number of permissible values, with the rest being forbidden. As long as circuit impairments are small enough so a permissible value is not moved to a forbidden state transmission is lossless. This is unlike analog transmission where noise constantly degrades the signal.
And now back to our regularly scheduled program
/tom |
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| reply to John Galt
said by John Galt:Do they run Cat5 from the CO or RTU...? No but is it shielded, bonded and grounded?
Hint. Yes. |
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batterupI Can Not Tell A Lie.Premium
join:2003-02-06
Netcong, NJ | said by xbell :said by John Galt:Do they run Cat5 from the CO or RTU...? No but is it shielded, bonded and grounded? Hint. Yes. It always has been; voice would not be acceptable and it would be hazardous if it were not. |
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batterupI Can Not Tell A Lie.Premium
join:2003-02-06
Netcong, NJ | reply to Killa200
said by Killa200:That always killed me thing about it, because this solution cuts down on the telco's costs of delivery by using 50% less copper, and the transport equipment has to be cheaper than the old stuff. Yet around here we still get charged ~$900 for a full t1 circuit that is about as stable as dsl due to OSP issues the telco just isn't going to fix. In Bell Tell/Bellatlantic/Verizon New Jersey T-1s would be put on copper as a last resort; the conditioning and maintainability was a killer. All T-1s came with a 98% up-time guarantee. If one went out at 3AM my phone and the register would ring. |
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| reply to tschmidt
said by tschmidt: Digital signaling is limited to a finite number of discrete values. That number may be very large, as in the case of discrete multi tone (DMT) modulation, used by ADSL. But it is nevertheless a discrete number of permissible values. This is why digital transmission can be lossless. There are a relatively small number of permissible values, with the rest being forbidden. /tom Basically, you are saying that touch-tone dialing is digital dialing. In fact it is analog tone recognition, which is not digital. There are 10 acceptable tones. Those tones are ALL analog events.
Dial-up modem connections use the same analog tone recognition. Does that make my dial-up connection a DIGITAL service? |
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tschmidtPremium,MVM
join:2000-11-12
Milford, NH
kudos:8 Reviews:
·G4 Communications
·Fairpoint Commun..
·Hollis Hosting
| said by Waterbug:you are saying that touch-tone dialing is digital dialing. In fact it is analog tone recognition, which is not digital. There are 10 acceptable tones. Those tones are ALL analog events. If you use that definition for analog vs digital then DSl and DOCSIS modems are analog as well at higher speed Ethernet and over the air and Cable HDTV. With he exception of optical there is no long distance high speed signaling that uses simple on/off digital signaling.
To play devils advocate Touch Tone transmits 12 discrete values (0-9 # * using seven discrete tones (eight if you include Autovon). There is noting "continuous" about it which is the hallmark of digital.
/tom |
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batterupI Can Not Tell A Lie.Premium
join:2003-02-06
Netcong, NJ | reply to dmxrob6
Just to beat this horse two computers connected by an RJ45 nul modem use digital four wire circuits. |
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