Under Development

Cat7: waiting in the wings

As gigabit and 10G Ethernet networks start making inroads, the need for speed and the ability to handle future applications will drive the adoption of Cat7 in India provided costs come down, says Sushma Naik

Category7 cabling is a recent improvement in cabling infrastructure technology. It consists of individually shielded four-pair twisted cable, with an intended operating frequency of 600 MHz.

Tyco says that the only deployment of a Cat7 network in the country is at the premises of its client, the Ship Building Corporation of India at Vizag. According to analysts, Cat7 is expected to capture 0.4 percent of the global market by 2006; the low number is largely because it is still to be ratified as an international standard.

“Cat7 cabling is a shielded twisted pair (STP) solution and not a normal UTP solution; this makes it expensive. Moreover, all the applications are available on Cat6 UTP, and only enterprises which want more speed will look at Cat7,” opines Vikas Pinjarkar, General Manager, Sales, D-Link India.

Having said that, companies which have a planning horizon of 10 years can justify the cost of a Cat7 deployment (cable and connectors) because it saves money vis-à-vis alternative cabling methods that handle applications requiring increased bandwidth. Also, early adopters of any new technology (such as 10G Ethernet) or companies concerned with electromagnetic interference in an environment (such as a factory floor) tend to use Cat7 cabling.

Eliminating alien crosstalk

“The next generation of cable standard—Cat6e or Cat7—is not yet finalised. Cat6 has 250 MHz frequency and supports gigabit speeds, whereas the IEEE and EIA/TIA are pushing 600 MHz frequency in Cat6e or Cat7 so that it will support 10 Gigabit Ethernet,” says Deepesh Krishnan, Business Development Manager, VDI, Legrand.

Cat7 cable currently comes with shielded foiled twisted pair (SFTP) inside an overall shield. It is designed for transmission frequencies of up to 600 MHz as an end-to end system, which should enable it to carry 10 Gigabit Ethernet (10GBaseT). Experts have proposed four individually-shielded pairs inside an overall shield, but this is not prevalent, says K K Shetty, Country Manager, AMP Netconnect, Tyco.

“The components are shielded and have a provision for earthing. This reduces the noise level drastically and improvises on the Signal-to-Noise (S/N) ratio. Secondly, Cat7 is tested at higher frequencies than Cat6. Thus, it is a more balanced system and can be used in a noisy environment due to its capacity to suppress EMI and RFI effects vis-à-vis normal Cat6 UTP systems,” adds Pinjarkar.

At 600 MHz bandwidth, Cat7 cabling is the highest for any type of copper cabling standard. Shetty says that previous cabling technologies were based on conservative performance standards such as Category 5e’s 100 MHz and Category 6’s 250 MHz. Cat7 is believed to have been tested successfully for 10 G transmission over copper cable much before Cat6A was invented, the reason being that Cat7 had already been tested at frequencies of 600 MHz and above, which is the basic requirement for 10 G transmissions. Secondly, Cat7 is an STP solution, and the distance between copper pairs within the cable as well as distance between adjacent cables is maintained to prevent alien crosstalk.

But not everybody buys into this argument, and some opine that Cat7 isn’t all that it’s made out to be. “The Indian structured cabling industry and system integrators are more comfortable deploying UTP solutions. Cat6 and Cat6A are the preferred choice; both are UTP solutions and are capable of supporting 10 Gigabit Ethernet on copper for up to 100 metres,” informs Pinjarkar.

Dileep Kumar, Technical & Product Manager, Enterprise, ADC Krone, says that there are different ways to eliminate crosstalk. “In Category7 cabling, crosstalk is eliminated through shielding. But with different innovative methods to eliminate crosstalk in UTP Category6A cable, the required crosstalk performance levels are achieved in the UTP cable itself. This makes Category7 cabling less attractive with no edge over UTP.”

Pain points

So can Cat7 succeed? Opinion is divided. Prasanna Kumar V, Director, India and SAARC, Systimax Solutions, lists a few disadvantages of Cat7. The cables are bulky and the connectors require individually shielded pairs; this isn’t installer-friendly. Individual pair shielding slows down termination time, requiring close attention to grounding and bonding. This translates to 10-15 minutes per connection as against less than 3 minutes for a conventional UTP connection. The proposed Cat7 solutions have two connector alternatives which are neither widely-accepted and nor user-friendly.

“Due to this, backward compatibility becomes a big question mark. The connectors are large, leading to issues of space in desks, walls and pathways. Most importantly, Cat7 plugs are not compatible with existing network equipment. That could mean additional investment,” Prasanna comments.

When will it arrive?

Cat7 will take time to get into the heart of Indian IT. This depends on how the standards for 10 G on Cat6 UTP evolve. “It must be noted that 10 G on UTP Cat6 systems can deliver only up to 250 MHz frequency. Those who are looking for higher frequency on their installation may need Cat7 systems. The future of Cat7 looks a bit bleak as its costs are higher when compared to a Cat6 UTP solution. With the rates of fibre optic cables going down, end-users will not hesitate to use fibre at the desktop with virtually unlimited bandwidth rather than go in for costly Cat7 STP solutions,” forecasts Pinjarkar.

India being a UTP market, Cat7 cabling seems less likely to gain acceptance because of installation difficulties. For cabling technology to become mainstream, an increasing number of equipment manufacturers need to design a Cat7 interface on their hardware. Companies will also have to grow accustomed to a different interface.

Cat7 may end up with many admirers, but it will take a few more years for that to happen.

sushma@expresscomputeronline.com