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GeneralRe: Serial cables... serial communications Pin
Member 798912215-Feb-19 0:23
MemberMember 798912215-Feb-19 0:23 
GeneralRe: Serial cables... serial communications Pin
Dean Roddey14-Feb-19 17:15
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GeneralRe: Serial cables... serial communications Pin
lowracer14-Feb-19 21:19
professionallowracer14-Feb-19 21:19 
GeneralRe: Serial cables... serial communications Pin
Member 916705714-Feb-19 21:54
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GeneralRe: Serial cables... serial communications Pin
JohnDG5214-Feb-19 23:26
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GeneralRe: Serial cables... serial communications Pin
Member 798912215-Feb-19 0:12
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GeneralRe: Serial cables... serial communications Pin
JohnDG5215-Feb-19 0:16
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GeneralRe: Serial cables... serial communications Pin
Member 798912215-Feb-19 2:13
MemberMember 798912215-Feb-19 2:13 
And it works over a 2 line connection, such as a POTS line.

BUT: It is not bit transparent. And it requires the sender to respond fast enough. The latency is generally a lot higher with software flow control.

I was teaching networks at college level in the 1990, when 622 Mbps B-ISDN and ATM was still an option, and optic fibers were becoming commonplace, running for 50 km or more without repeaters. (They could run for much greater distances even in the 1990s, but towns are usually no further apart.) I used to start first lecture on B-ISDN with a question: How big is a bit? How many centimeters long? Light in a fiber moves at roughly 200,000,000 m/s. If you sende 622,000,000 per second, that gives them about 30 cm each. Before the first bit has come to the end of a 50,000 m long fiber, you have poured in more than 150,000 bits. And before the STOP!!! signal has come back to you, you have sent another 150,000 bits down the line. Now, let us see how well our basic frame mechanimsm from lower speed lines works under those conditions...

Lots of the students first thought I had made an error in the calculation, missing by a factor of a thousand. After checking and counting zeroes, they shook their head with a "But... What shall we do then?". (The next layer-1 protocol we treated was DQDB - another now forgotten alternative, which is a pity; it did have something going, with its reservation scheme. It never made any success, but we should learn for failures, too - failure in the market doesn't prove that it was without merits. Around 1990 it taught the students that there is more than one way to skin a flow control cat!)
GeneralRe: Serial cables... serial communications Pin
Peter Shaw15-Feb-19 1:19
professionalPeter Shaw15-Feb-19 1:19 
GeneralRe: Serial cables... serial communications Pin
charlieg15-Feb-19 2:08
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GeneralRe: Serial cables... serial communications Pin
Greg Lovekamp15-Feb-19 3:55
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GeneralRe: Serial cables... serial communications Pin
OriginalGriff15-Feb-19 4:43
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GeneralRe: Serial cables... serial communications Pin
Greg Lovekamp15-Feb-19 5:19
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GeneralRe: Serial cables... serial communications Pin
OriginalGriff15-Feb-19 5:22
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GeneralRe: Serial cables... serial communications Pin
Member 1315692715-Feb-19 4:39
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GeneralRe: Serial cables... serial communications Pin
SeattleC++15-Feb-19 5:09
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GeneralRe: Serial cables... serial communications Pin
ttennebb15-Feb-19 10:26
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GeneralRe: Serial cables... serial communications Pin
charlieg17-Feb-19 11:42
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JokeThought for some other day... Pin
littleGreenDude14-Feb-19 2:36
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GeneralRe: Thought for some other day... Pin
OriginalGriff14-Feb-19 2:42
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GeneralRe: Thought for some other day... Pin
Mike Hankey14-Feb-19 3:38
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GeneralRe: Thought for some other day... Pin
OriginalGriff14-Feb-19 4:01
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GeneralRe: Thought for some other day... Pin
Mike Hankey14-Feb-19 4:20
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GeneralRe: Thought for some other day... Pin
OriginalGriff14-Feb-19 4:31
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GeneralRe: Thought for some other day... Pin
Mike Hankey14-Feb-19 4:37
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