Re: Packet delivery on a Ethernet Wire

If all 4 pairs are used in 1000Base-T I wonder how POE also rolls into
that...

On Sun, Jul 31, 2011 at 1:55 PM, Carlos G Mendioroz <tron_at_huapi.ba.ar>wrote:

> On 1G 1000BASE-T, pairs are bidirectional, full duplex.
> (Like your POTS phone line, you can talk while you listen)
> No collisions.
> Signal treatment is beyong my current understanding, but it uses 5 levels
> in each pair!
> Amazing...
>
>
> Irfan Sid @ 31/07/2011 11:32 -0300 dixit:
>
>>
>> On 1 Gig link pin 4,5, 7 and 8 are bi-directional meaning the same wire
>> will be used for Tx and Rx?
>> And for 10/100 those pins are not used at all, so 10/100 is serial
>> rather then parrallel.
>> Does that mean that odd collison is possible on both since they are
>> bidirectional packet streams??
>>
>>
>> http://pinouts.ws/rj-45-**pinout.html<http://pinouts.ws/rj-45-pinout.html>
>>
>>
>> http://pinouts.ru/Net/**Ethernet10BaseT_pinout.shtml<http://pinouts.ru/Net/Ethernet10BaseT_pinout.shtml>
>>
>>
>>
>>
>> On Sun, Jul 31, 2011 at 2:50 PM, Carlos G Mendioroz <tron_at_huapi.ba.ar<mailto:
>> tron_at_huapi.ba.ar>> wrote:
>>
>> I stand corrected, in 1000BASE-T there are 4 bidirectional signal
>> paths,
>> so it's basically a parallel interface.
>>
>> Sorry about that.
>> -Carlos
>>
>> Aaron Riemer @ 31/07/2011 05:36 -0300 dixit:
>>
>> Yep. However just doing some reading it looks like Gigabit copper
>> (1000BaseT) uses all four pairs and this link seems to suggest
>> that data is
>> sent in parallel.
>> http://www.cisco.com/en/US/__**tech/tk389/tk214/tech___**
>> digest09186a0080091a86.html<http://www.cisco.com/en/US/__tech/tk389/tk214/tech___digest09186a0080091a86.html>
>> <http://www.cisco.com/en/US/**tech/tk389/tk214/tech_**
>> digest09186a0080091a86.html<http://www.cisco.com/en/US/tech/tk389/tk214/tech_digest09186a0080091a86.html>
>> >
>>
>> "1000BASE-T works by using all four of the Category 5 pairs to
>> achieve 1000
>> Mbps operation over the installed Category 5 copper cabling.
>> 1000 Mbps data
>> rates are achieved by sending and receiving a 250 Mbps data
>> stream over each
>> of the four pairs simultaneously (4 X 250 Mbps = 1 Gbps)."
>>
>>
>>
>> Cheers,
>>
>> -Aaron.
>>
>>
>>
>> -----Original Message-----
>> From: nobody_at_groupstudy.com <mailto:nobody_at_groupstudy.com>
>> [mailto:nobody_at_groupstudy.com <mailto:nobody_at_groupstudy.com>**] On
>>
>> Behalf Of
>> Irfan Sid
>> Sent: Sunday, 31 July 2011 1:02 PM
>> To: Aaron Riemer
>> Cc: Carlos G Mendioroz; Cisco certification; Cisco certification
>> Subject: Re: Packet delivery on a Ethernet Wire
>>
>> So does that mean that in copper wire, you have two paths ie
>> full duplex,
>> one for transmit and one for recieve. One pair of the copper will
>> be
>> dedicated to tansmit and one to recieve. Each path transmitting
>> serially.
>>
>> On Fibre its the same, you have two fibre's one for transmit and
>> one for
>> receive and data is transmitted serially on them.
>>
>> Is this correct?
>>
>> On Thu, Jul 28, 2011 at 6:07 AM, Aaron Riemer
>> <ariemer_at_amnet.net.au <mailto:ariemer_at_amnet.net.au>> wrote:
>>
>> My apologies. I must have misread.
>>
>> http://en.wikipedia.org/wiki/_**_Data_transmission<http://en.wikipedia.org/wiki/__Data_transmission>
>> <http://en.wikipedia.org/wiki/**Data_transmission<http://en.wikipedia.org/wiki/Data_transmission>
>> >
>>
>> Thanks for clearing that up.
>>
>> Cheers,
>>
>> -Aaron.
>>
>> -----Original Message-----
>> From: nobody_at_groupstudy.com <mailto:nobody_at_groupstudy.com>
>> [mailto:nobody_at_groupstudy.com
>>
>> <mailto:nobody_at_groupstudy.com>**] On Behalf Of
>> Carlos G Mendioroz
>> Sent: Thursday, 28 July 2011 12:27 AM
>> To: Aaron Riemer
>> Cc: 'Irfan Sid'; 'Cisco certification'; 'Cisco certification'
>> Subject: Re: Packet delivery on a Ethernet Wire
>>
>> Aaron,
>> copper has "pairs" because you use one wire as a reference
>> to the other.
>> But there is only one signal path (each way), and it works
>> serially.
>> -Carlos
>>
>> Aaron Riemer @ 27/7/2011 4:09 -0300 dixit:
>>
>> Hi Irfan,
>>
>> I believe with copper Ethernet (100BaseTX for example)
>> since there are
>> copper "pairs" the data is sent in parallel. I would
>> assume the only way
>> parallel data transmission would work with fibre is if a
>> different band
>>
>> of
>>
>> light is used (CWDM for example).
>>
>> Queuing on the router/switch only affects packets within
>> the router
>>
>> itself
>>
>> and has no bearing on packets along the wire (unless
>> they are dropped).
>>
>> Tools such as compression / LFI / DSCP marking are
>> examples of the
>>
>> router
>>
>> manipulating the packets in some way before transmission
>> out an
>>
>> interface.
>>
>> Cheers,
>>
>> -Aaron.
>>
>>
>> -----Original Message-----
>> From: nobody_at_groupstudy.com
>> <mailto:nobody_at_groupstudy.com>
>> [mailto:nobody_at_groupstudy.com
>>
>> <mailto:nobody_at_groupstudy.com>**] On Behalf Of
>> Irfan Sid
>> Sent: Wednesday, 27 July 2011 1:48 PM
>> To: Cisco certification; Cisco certification
>> Subject: Packet delivery on a Ethernet Wire
>>
>> This maybe a stupid question would appreciate if someone
>> can clearify:
>>
>> Are Ethernet packets delivered serially on the physcial
>> medium ie copper
>>
>> or
>>
>> fibre - one after another in one single file or line if
>> you will. Or are
>> they delivered in parallel ie. two or more packets can be
>> in
>>
>> transmission
>>
>> along each other in parallel.
>>
>> Also when you enable queueing on Router/switch. Does
>> this only effect
>>
>> the
>>
>> behaviour of how the router treats the packet on the
>> inbound or outbound
>> interface or does it also effect the behaviour of the
>> packet when it is
>> actually in transit on the wire itself.
>>
>>
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>>
>>
>>
>>
>>
>>
>> --
>> Carlos G Mendioroz <tron_at_huapi.ba.ar
>> <mailto:tron_at_huapi.ba.ar>> LW7 EQI Argentina
>>
>>
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>>
>>
>>
>> -- Carlos G Mendioroz <tron_at_huapi.ba.ar <mailto:tron_at_huapi.ba.ar
>> >>
>> LW7 EQI Argentina
>>
>>
>>
> --
> Carlos G Mendioroz <tron_at_huapi.ba.ar> LW7 EQI Argentina
>
>
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Blog: http://astorinonetworks.com
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