connectix
Copper 100G Ethernet?
News : May 22, 2007
Yes, there is a movement within the IEEE Higher Speed Study Group to come up with a standard to run 100 Gigabit Ethernet over fibre-optic lines but also, more surprisingly, over copper wiring.
The distances that are being discussed for copper are short, just enough to link kit in neighbouring cabinets.
To put the target into perspective, the IEEE 802.3an 10GBase-T standard for running 10G over unshielded twisted pair wiring can stretch 100 metres and was once thought to be highly unlikely in the real world environment. The IEEE 802.3ak 10GBase-CX4 standard runs 10 Gigabit Ethernet over twin-axial copper cabling, but only over 15 metres or so.
The new proposal on 100G is for taking an approach similar to that of 10GBase-CX4, where twin-axial or coaxial cabling would be used, with the intention of using such connections pretty exclusively for connections between racks in a data centre. The study group is talking about 5 to 10 metres as a maximum.
Mike Bennett of Lawrence Berkeley National Laboratory in the US often gives the IEEE the perspective of the leading edge of Ethernet. He gave a presentation to the study group earlier this month stating the need for a copper 100G interconnect. Bennett argued there would be demand for 5 metres, but longer would be better, distances just has to be long enough to get from one rack to another.
Others gave presentations stating that technical feasibility, economic feasibility and market potential would all be demonstrated.
This means that 100 Gigabit Ethernet over copper could become a reality but, and it is a big but, these specialist copper cables will have to compete with fibre, a technology that does not have the Alien Cross Talk (AXTalk) issues.
There are several companies developing special ribbon and loose tube cables that will interface with MPO/MTP connectors, which are likely to give the bandwidth performance and cable management solution that 100 Gigabit Ethernet sites will require.
To put the target into perspective, the IEEE 802.3an 10GBase-T standard for running 10G over unshielded twisted pair wiring can stretch 100 metres and was once thought to be highly unlikely in the real world environment. The IEEE 802.3ak 10GBase-CX4 standard runs 10 Gigabit Ethernet over twin-axial copper cabling, but only over 15 metres or so.
The new proposal on 100G is for taking an approach similar to that of 10GBase-CX4, where twin-axial or coaxial cabling would be used, with the intention of using such connections pretty exclusively for connections between racks in a data centre. The study group is talking about 5 to 10 metres as a maximum.
Mike Bennett of Lawrence Berkeley National Laboratory in the US often gives the IEEE the perspective of the leading edge of Ethernet. He gave a presentation to the study group earlier this month stating the need for a copper 100G interconnect. Bennett argued there would be demand for 5 metres, but longer would be better, distances just has to be long enough to get from one rack to another.
Others gave presentations stating that technical feasibility, economic feasibility and market potential would all be demonstrated.
This means that 100 Gigabit Ethernet over copper could become a reality but, and it is a big but, these specialist copper cables will have to compete with fibre, a technology that does not have the Alien Cross Talk (AXTalk) issues.
There are several companies developing special ribbon and loose tube cables that will interface with MPO/MTP connectors, which are likely to give the bandwidth performance and cable management solution that 100 Gigabit Ethernet sites will require.
