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Do network adapters read incoming bits in a single stream?
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When a Gigabit network adapter is receiving data, how is it receiving the bits?
Is it seeing it all in one stream of 0's and 1's? Or is there somehow multiple streams of 0's and 1's coming in at the same time?
For example... let's say there's two sending devices and one receiving device.
Devices 1 and 2 start sending network data to Device 3 at the same time.
My assumption is that from Device 3's Network adapter's point of view, all the 0's and 1's are coming across in a single stream of data. It can figure out what data is from Device 1 or 2, but the data is still just one stream of millions/billions of bits.
Am i totally wrong? :)
ethernet layer1 networking
edited 29 mins ago
jonathanjo
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up vote
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down vote
favorite
When a Gigabit network adapter is receiving data, how is it receiving the bits?
Is it seeing it all in one stream of 0's and 1's? Or is there somehow multiple streams of 0's and 1's coming in at the same time?
For example... let's say there's two sending devices and one receiving device.
Devices 1 and 2 start sending network data to Device 3 at the same time.
My assumption is that from Device 3's Network adapter's point of view, all the 0's and 1's are coming across in a single stream of data. It can figure out what data is from Device 1 or 2, but the data is still just one stream of millions/billions of bits.
Am i totally wrong? :)
ethernet layer1 networking
edited 29 mins ago
jonathanjo
6,680423
asked 49 mins ago
shihku7
61
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shihku7 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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Do you mean for a half-duplex connection, or using full-duplex? There were never any half-duplex devices for 1000Base-T, even though it is still in that standard. With a full-duplex connection, there would not be frames from two devices contending for the third device at the same time on the link.
– Ron Maupin♦
47 mins ago
full-duplex. OK, so, there'd still be a single stream of 0's and 1's (ex: 01010101010001010010101001010100001101011010) and from Device 3's point of view (the receiver), while Device 1 and 2 could take turns on that stream, they'd never both be sending 0's and 1's at the exact same time, right?
– shihku7
42 mins ago
add a comment |Â
up vote
1
down vote
favorite
up vote
1
down vote
favorite
When a Gigabit network adapter is receiving data, how is it receiving the bits?
Is it seeing it all in one stream of 0's and 1's? Or is there somehow multiple streams of 0's and 1's coming in at the same time?
For example... let's say there's two sending devices and one receiving device.
Devices 1 and 2 start sending network data to Device 3 at the same time.
My assumption is that from Device 3's Network adapter's point of view, all the 0's and 1's are coming across in a single stream of data. It can figure out what data is from Device 1 or 2, but the data is still just one stream of millions/billions of bits.
Am i totally wrong? :)
ethernet layer1 networking
edited 29 mins ago
jonathanjo
6,680423
asked 49 mins ago
shihku7
61
New contributor
shihku7 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
When a Gigabit network adapter is receiving data, how is it receiving the bits?
Is it seeing it all in one stream of 0's and 1's? Or is there somehow multiple streams of 0's and 1's coming in at the same time?
For example... let's say there's two sending devices and one receiving device.
Devices 1 and 2 start sending network data to Device 3 at the same time.
My assumption is that from Device 3's Network adapter's point of view, all the 0's and 1's are coming across in a single stream of data. It can figure out what data is from Device 1 or 2, but the data is still just one stream of millions/billions of bits.
Am i totally wrong? :)
ethernet layer1 networking
ethernet layer1 networking
edited 29 mins ago
jonathanjo
6,680423
asked 49 mins ago
shihku7
61
New contributor
shihku7 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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edited 29 mins ago
jonathanjo
6,680423
asked 49 mins ago
shihku7
61
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shihku7 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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edited 29 mins ago
jonathanjo
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edited 29 mins ago
jonathanjo
6,680423
edited 29 mins ago
jonathanjo
6,680423
6,680423
asked 49 mins ago
shihku7
61
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asked 49 mins ago
shihku7
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asked 49 mins ago
shihku7
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61
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shihku7 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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New contributor
shihku7 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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Check out our Code of Conduct.
Do you mean for a half-duplex connection, or using full-duplex? There were never any half-duplex devices for 1000Base-T, even though it is still in that standard. With a full-duplex connection, there would not be frames from two devices contending for the third device at the same time on the link.
– Ron Maupin♦
47 mins ago
full-duplex. OK, so, there'd still be a single stream of 0's and 1's (ex: 01010101010001010010101001010100001101011010) and from Device 3's point of view (the receiver), while Device 1 and 2 could take turns on that stream, they'd never both be sending 0's and 1's at the exact same time, right?
– shihku7
42 mins ago
add a comment |Â
Do you mean for a half-duplex connection, or using full-duplex? There were never any half-duplex devices for 1000Base-T, even though it is still in that standard. With a full-duplex connection, there would not be frames from two devices contending for the third device at the same time on the link.
– Ron Maupin♦
47 mins ago
full-duplex. OK, so, there'd still be a single stream of 0's and 1's (ex: 01010101010001010010101001010100001101011010) and from Device 3's point of view (the receiver), while Device 1 and 2 could take turns on that stream, they'd never both be sending 0's and 1's at the exact same time, right?
– shihku7
42 mins ago
Do you mean for a half-duplex connection, or using full-duplex? There were never any half-duplex devices for 1000Base-T, even though it is still in that standard. With a full-duplex connection, there would not be frames from two devices contending for the third device at the same time on the link.
– Ron Maupin♦
47 mins ago
Do you mean for a half-duplex connection, or using full-duplex? There were never any half-duplex devices for 1000Base-T, even though it is still in that standard. With a full-duplex connection, there would not be frames from two devices contending for the third device at the same time on the link.
– Ron Maupin♦
47 mins ago
full-duplex. OK, so, there'd still be a single stream of 0's and 1's (ex: 01010101010001010010101001010100001101011010) and from Device 3's point of view (the receiver), while Device 1 and 2 could take turns on that stream, they'd never both be sending 0's and 1's at the exact same time, right?
– shihku7
42 mins ago
full-duplex. OK, so, there'd still be a single stream of 0's and 1's (ex: 01010101010001010010101001010100001101011010) and from Device 3's point of view (the receiver), while Device 1 and 2 could take turns on that stream, they'd never both be sending 0's and 1's at the exact same time, right?
– shihku7
42 mins ago
add a comment |Â
3 Answers
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up vote
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down vote
It depends.
While many Ethernet PHYs transmit data in a purely serial fashion (e.g. 100BASE-TX, 1000BASE-SX, 10GBASE-SR), some split the data stream into multiple lanes that are transmitted in parallel.
Most commonly, 1000BASE-T - the common gigabit-over-copper variant - splits the encoded data stream into four lanes and transmits each separately on one of the four twisted pairs in a Cat-5 cable. All copper variants from gigabit upwards use these four lanes.
Some high-speed (10G+) fiber PHYs also use up to ten fibers (with multi-mode fiber and short range) or wavelengths (with single-mode fiber and long range).
However, everything is transmitted in frames that each run from a single source to a single destination. Frames are generally atomic. When the network receives two frames from different sources for the same destination at the same time, one of the frames needs to be queued until the destination's port has finished receiving the first frame.
This assumes that sources and destination run at the same speed which isn't necessarily true. You could have a file server connected by a 1 Gbit/s link and ten clients each sending full speed on their 100 Mbit/s links with (nearly) no queueing.
answered 31 mins ago
Zac67
21.2k21148
add a comment |Â
up vote
2
down vote
This particular case is a complex one.
Regarding 1000baseT.
First: when we say two devices are transmitting at the same time, they are not normally actually sending bits at the same instant on the same medium. If they do so, there is a collision and all the listening devices work this out (eventually, through various collision detection schemes.) So your two transmitting devices will gain access to the medium at slightly different moments. But there are actually normally only two devices on a given set of pairs; normally one device is a switch and the other is a host.
Second, 1000baseT transmits at eight voltage levels, sending three bits at any given instant. So it's a series of octal digits on the wire, not a series of bits. These eight voltage levels are essentially representing two data bits plus error detection.
Third, 1000baseT can transmit in both directions at the same time, on the same pair. It can separate the outgoing signal from the incoming one by a circuit called a hybrid.
Gigabit ethernet over other media behaves differently. Slower speeds eg 10baseT and 100baseT have simpler schemes. 10baseT over a hub really does have actual collisions; over switches it's normally organised by the switch so that outgoing frames are queued; if it's full duplex there are no collisions at all.
answered 34 mins ago
jonathanjo
6,680423
add a comment |Â
up vote
2
down vote
I think you need to get some basic understanding of how ethernet works. For example, the sending host will send a preamble of alternating ones and zeroes to get the attention of the receiving host. When the receiving host sees two ones in a row, it knows that the frame is next. Once the frame is transmitted, then there must be silence on the line for 96 bits before another frame is sent.
Different ethernet standards will use different encoding. For example, 100Base-T uses 4B5B that sends five bits for every four bits of data.
answered 33 mins ago
Ron Maupin♦
58k1056101
add a comment |Â
3 Answers
3
active
oldest
votes
3 Answers
3
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
3
down vote
It depends.
While many Ethernet PHYs transmit data in a purely serial fashion (e.g. 100BASE-TX, 1000BASE-SX, 10GBASE-SR), some split the data stream into multiple lanes that are transmitted in parallel.
Most commonly, 1000BASE-T - the common gigabit-over-copper variant - splits the encoded data stream into four lanes and transmits each separately on one of the four twisted pairs in a Cat-5 cable. All copper variants from gigabit upwards use these four lanes.
Some high-speed (10G+) fiber PHYs also use up to ten fibers (with multi-mode fiber and short range) or wavelengths (with single-mode fiber and long range).
However, everything is transmitted in frames that each run from a single source to a single destination. Frames are generally atomic. When the network receives two frames from different sources for the same destination at the same time, one of the frames needs to be queued until the destination's port has finished receiving the first frame.
This assumes that sources and destination run at the same speed which isn't necessarily true. You could have a file server connected by a 1 Gbit/s link and ten clients each sending full speed on their 100 Mbit/s links with (nearly) no queueing.
answered 31 mins ago
Zac67
21.2k21148
add a comment |Â
up vote
3
down vote
It depends.
While many Ethernet PHYs transmit data in a purely serial fashion (e.g. 100BASE-TX, 1000BASE-SX, 10GBASE-SR), some split the data stream into multiple lanes that are transmitted in parallel.
Most commonly, 1000BASE-T - the common gigabit-over-copper variant - splits the encoded data stream into four lanes and transmits each separately on one of the four twisted pairs in a Cat-5 cable. All copper variants from gigabit upwards use these four lanes.
Some high-speed (10G+) fiber PHYs also use up to ten fibers (with multi-mode fiber and short range) or wavelengths (with single-mode fiber and long range).
However, everything is transmitted in frames that each run from a single source to a single destination. Frames are generally atomic. When the network receives two frames from different sources for the same destination at the same time, one of the frames needs to be queued until the destination's port has finished receiving the first frame.
This assumes that sources and destination run at the same speed which isn't necessarily true. You could have a file server connected by a 1 Gbit/s link and ten clients each sending full speed on their 100 Mbit/s links with (nearly) no queueing.
answered 31 mins ago
Zac67
21.2k21148
add a comment |Â
up vote
3
down vote
up vote
3
down vote
It depends.
While many Ethernet PHYs transmit data in a purely serial fashion (e.g. 100BASE-TX, 1000BASE-SX, 10GBASE-SR), some split the data stream into multiple lanes that are transmitted in parallel.
Most commonly, 1000BASE-T - the common gigabit-over-copper variant - splits the encoded data stream into four lanes and transmits each separately on one of the four twisted pairs in a Cat-5 cable. All copper variants from gigabit upwards use these four lanes.
Some high-speed (10G+) fiber PHYs also use up to ten fibers (with multi-mode fiber and short range) or wavelengths (with single-mode fiber and long range).
However, everything is transmitted in frames that each run from a single source to a single destination. Frames are generally atomic. When the network receives two frames from different sources for the same destination at the same time, one of the frames needs to be queued until the destination's port has finished receiving the first frame.
This assumes that sources and destination run at the same speed which isn't necessarily true. You could have a file server connected by a 1 Gbit/s link and ten clients each sending full speed on their 100 Mbit/s links with (nearly) no queueing.
answered 31 mins ago
Zac67
21.2k21148
It depends.
While many Ethernet PHYs transmit data in a purely serial fashion (e.g. 100BASE-TX, 1000BASE-SX, 10GBASE-SR), some split the data stream into multiple lanes that are transmitted in parallel.
Most commonly, 1000BASE-T - the common gigabit-over-copper variant - splits the encoded data stream into four lanes and transmits each separately on one of the four twisted pairs in a Cat-5 cable. All copper variants from gigabit upwards use these four lanes.
Some high-speed (10G+) fiber PHYs also use up to ten fibers (with multi-mode fiber and short range) or wavelengths (with single-mode fiber and long range).
However, everything is transmitted in frames that each run from a single source to a single destination. Frames are generally atomic. When the network receives two frames from different sources for the same destination at the same time, one of the frames needs to be queued until the destination's port has finished receiving the first frame.
This assumes that sources and destination run at the same speed which isn't necessarily true. You could have a file server connected by a 1 Gbit/s link and ten clients each sending full speed on their 100 Mbit/s links with (nearly) no queueing.
answered 31 mins ago
Zac67
21.2k21148
answered 31 mins ago
Zac67
21.2k21148
answered 31 mins ago
Zac67
21.2k21148
answered 31 mins ago
Zac67
21.2k21148
21.2k21148
add a comment |Â
add a comment |Â
up vote
2
down vote
This particular case is a complex one.
Regarding 1000baseT.
First: when we say two devices are transmitting at the same time, they are not normally actually sending bits at the same instant on the same medium. If they do so, there is a collision and all the listening devices work this out (eventually, through various collision detection schemes.) So your two transmitting devices will gain access to the medium at slightly different moments. But there are actually normally only two devices on a given set of pairs; normally one device is a switch and the other is a host.
Second, 1000baseT transmits at eight voltage levels, sending three bits at any given instant. So it's a series of octal digits on the wire, not a series of bits. These eight voltage levels are essentially representing two data bits plus error detection.
Third, 1000baseT can transmit in both directions at the same time, on the same pair. It can separate the outgoing signal from the incoming one by a circuit called a hybrid.
Gigabit ethernet over other media behaves differently. Slower speeds eg 10baseT and 100baseT have simpler schemes. 10baseT over a hub really does have actual collisions; over switches it's normally organised by the switch so that outgoing frames are queued; if it's full duplex there are no collisions at all.
answered 34 mins ago
jonathanjo
6,680423
add a comment |Â
up vote
2
down vote
This particular case is a complex one.
Regarding 1000baseT.
First: when we say two devices are transmitting at the same time, they are not normally actually sending bits at the same instant on the same medium. If they do so, there is a collision and all the listening devices work this out (eventually, through various collision detection schemes.) So your two transmitting devices will gain access to the medium at slightly different moments. But there are actually normally only two devices on a given set of pairs; normally one device is a switch and the other is a host.
Second, 1000baseT transmits at eight voltage levels, sending three bits at any given instant. So it's a series of octal digits on the wire, not a series of bits. These eight voltage levels are essentially representing two data bits plus error detection.
Third, 1000baseT can transmit in both directions at the same time, on the same pair. It can separate the outgoing signal from the incoming one by a circuit called a hybrid.
Gigabit ethernet over other media behaves differently. Slower speeds eg 10baseT and 100baseT have simpler schemes. 10baseT over a hub really does have actual collisions; over switches it's normally organised by the switch so that outgoing frames are queued; if it's full duplex there are no collisions at all.
answered 34 mins ago
jonathanjo
6,680423
add a comment |Â
up vote
2
down vote
up vote
2
down vote
This particular case is a complex one.
Regarding 1000baseT.
First: when we say two devices are transmitting at the same time, they are not normally actually sending bits at the same instant on the same medium. If they do so, there is a collision and all the listening devices work this out (eventually, through various collision detection schemes.) So your two transmitting devices will gain access to the medium at slightly different moments. But there are actually normally only two devices on a given set of pairs; normally one device is a switch and the other is a host.
Second, 1000baseT transmits at eight voltage levels, sending three bits at any given instant. So it's a series of octal digits on the wire, not a series of bits. These eight voltage levels are essentially representing two data bits plus error detection.
Third, 1000baseT can transmit in both directions at the same time, on the same pair. It can separate the outgoing signal from the incoming one by a circuit called a hybrid.
Gigabit ethernet over other media behaves differently. Slower speeds eg 10baseT and 100baseT have simpler schemes. 10baseT over a hub really does have actual collisions; over switches it's normally organised by the switch so that outgoing frames are queued; if it's full duplex there are no collisions at all.
answered 34 mins ago
jonathanjo
6,680423
This particular case is a complex one.
Regarding 1000baseT.
First: when we say two devices are transmitting at the same time, they are not normally actually sending bits at the same instant on the same medium. If they do so, there is a collision and all the listening devices work this out (eventually, through various collision detection schemes.) So your two transmitting devices will gain access to the medium at slightly different moments. But there are actually normally only two devices on a given set of pairs; normally one device is a switch and the other is a host.
Second, 1000baseT transmits at eight voltage levels, sending three bits at any given instant. So it's a series of octal digits on the wire, not a series of bits. These eight voltage levels are essentially representing two data bits plus error detection.
Third, 1000baseT can transmit in both directions at the same time, on the same pair. It can separate the outgoing signal from the incoming one by a circuit called a hybrid.
Gigabit ethernet over other media behaves differently. Slower speeds eg 10baseT and 100baseT have simpler schemes. 10baseT over a hub really does have actual collisions; over switches it's normally organised by the switch so that outgoing frames are queued; if it's full duplex there are no collisions at all.
answered 34 mins ago
jonathanjo
6,680423
answered 34 mins ago
jonathanjo
6,680423
answered 34 mins ago
jonathanjo
6,680423
answered 34 mins ago
jonathanjo
6,680423
6,680423
add a comment |Â
add a comment |Â
up vote
2
down vote
I think you need to get some basic understanding of how ethernet works. For example, the sending host will send a preamble of alternating ones and zeroes to get the attention of the receiving host. When the receiving host sees two ones in a row, it knows that the frame is next. Once the frame is transmitted, then there must be silence on the line for 96 bits before another frame is sent.
Different ethernet standards will use different encoding. For example, 100Base-T uses 4B5B that sends five bits for every four bits of data.
answered 33 mins ago
Ron Maupin♦
58k1056101
add a comment |Â
up vote
2
down vote
I think you need to get some basic understanding of how ethernet works. For example, the sending host will send a preamble of alternating ones and zeroes to get the attention of the receiving host. When the receiving host sees two ones in a row, it knows that the frame is next. Once the frame is transmitted, then there must be silence on the line for 96 bits before another frame is sent.
Different ethernet standards will use different encoding. For example, 100Base-T uses 4B5B that sends five bits for every four bits of data.
answered 33 mins ago
Ron Maupin♦
58k1056101
add a comment |Â
up vote
2
down vote
up vote
2
down vote
I think you need to get some basic understanding of how ethernet works. For example, the sending host will send a preamble of alternating ones and zeroes to get the attention of the receiving host. When the receiving host sees two ones in a row, it knows that the frame is next. Once the frame is transmitted, then there must be silence on the line for 96 bits before another frame is sent.
Different ethernet standards will use different encoding. For example, 100Base-T uses 4B5B that sends five bits for every four bits of data.
answered 33 mins ago
Ron Maupin♦
58k1056101
I think you need to get some basic understanding of how ethernet works. For example, the sending host will send a preamble of alternating ones and zeroes to get the attention of the receiving host. When the receiving host sees two ones in a row, it knows that the frame is next. Once the frame is transmitted, then there must be silence on the line for 96 bits before another frame is sent.
Different ethernet standards will use different encoding. For example, 100Base-T uses 4B5B that sends five bits for every four bits of data.
answered 33 mins ago
Ron Maupin♦
58k1056101
answered 33 mins ago
Ron Maupin♦
58k1056101
answered 33 mins ago
Ron Maupin♦
58k1056101
answered 33 mins ago
Ron Maupin♦
58k1056101
58k1056101
add a comment |Â
add a comment |Â
shihku7 is a new contributor. Be nice, and check out our Code of Conduct.
shihku7 is a new contributor. Be nice, and check out our Code of Conduct.
shihku7 is a new contributor. Be nice, and check out our Code of Conduct.
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Do you mean for a half-duplex connection, or using full-duplex? There were never any half-duplex devices for 1000Base-T, even though it is still in that standard. With a full-duplex connection, there would not be frames from two devices contending for the third device at the same time on the link.
– Ron Maupin♦
47 mins ago
full-duplex. OK, so, there'd still be a single stream of 0's and 1's (ex: 01010101010001010010101001010100001101011010) and from Device 3's point of view (the receiver), while Device 1 and 2 could take turns on that stream, they'd never both be sending 0's and 1's at the exact same time, right?
– shihku7
42 mins ago