10Gb Ethernet is will provide more bandwidth and speed for networking, but it’s hasn’t really grown the way that vendors expected. In my experience, 10GbE has some real problems that will make it grow gradually and organically, rather than force a new round of investment in networking.
The Problems with 10GB Ethernet
If you are using copper patch leads for 10GbE, you are going to a need a lot of power. Using standard copper can use up to 45W per port (although 10GBaseCX-4 apparently uses 4.5W per port).
The IEEE is working on Energy Efficient Ethernet (802.3az) technology that will allow links to auto-negotiate down to lower speeds or go to “sleep’ during periods of inactivity which will further reduce power consumption.
10GBaseT copper uses 650Mhz frequency spectrum and needs high quality cabling to work reliably. This means that you need to test, properly, your existing Cat5 or replace it with Cat6A or better. If you use Cat6A or even Cat6, the cable is physically much larger (and you may not have the space in your computer room). In this case, you will have up to 100 metre cable length. If you use Cat5 or Cat5e, the distance is much shorter depending on the quality of your cable, typically less than 40 metres and would probably need testing for assured reliability.
10GBaseSR uses multimode cabling but has different cable lengths depending on type of cabling and certain combinations will require mode conditioning patch leads.
The current list of 10GB XENPAK / X2 interfaces from Cisco show the confusion that the different types of cabling causes. For example consider the following table showing the LAN options (I’ve removed the WAN units) and the variation in cabling types:
|X2 Product ID||XENPAK Product ID||Transceiver Type||Wavelength||IEEE Standard||Maximum Distance/Cable Type|
|X2-10GB-LRM||XENPAK-10GB-LRM||10GBASE-LRM||1310 nm serial||802.3aq||220m over multimode fiber|
|X2-10GB-SR||XENPAK-10GB-SR||10GBASE-SR||850 nm serial||802.3ae||
26m over 62.5-micron FDDI grade multimode fiber
33m over 62.5-micron 200 MHz x km multimode fiber
66m over 50-micron 400 MHz x km multimode fiber
82m over 50-micron 500 MHz x km multimode fiber
300m over 50-micron 2000 MHz x km multimode fiber
|X2-10GB-LR||XENPAK-10GB-LR+||10GBASE-LR||1310 nm serial||802.3ae||10 km over single-mode fiber|
|X2-10GB-ER||XENPAK-10GB-ER+||10GBASE-ER||1550 nm serial||802.3ae||40 km over single-mode fiber|
|X2-10GB-LX4||XENPAK-10GB-LX4||10GBASE-LX4||WWDM 1310 nm||802.3ae||
300m over 62.5-micron FDDI grade multimode fiber
240m over 50-micron 400 MHz x km multimode fiber
300m over 50-micron 500 MHz x km multimode fiber
|X2-10GB-CX4||XENPAK-10GB-CX4||10GBASE-CX4||Copper||802.3ak||15m over 8 pair 100-Ohm InfiniBand cable|
The impact of cabling
In a recent project to plan a refit of an existing data centre, the 10GbE cabling needs was a major problem. Because of constraints in the change control and risk management, we eventually decided to use 1Gb ethernet because the time needed to get long change windows exceeded the length of the project.
And in other projects, the cost of recabling the fibre optic to meet the new requirement for 10GbE was prohibitive for smaller works. That is, we couldn’t just add a “patch of green” to an existing facility and extend the new switch as funds became available.
Which is weird, because it reminds me of the Token Ring / FDDI / Ethernet wars back in 1995 or so.
If you take the time build budgetary pricing around a Cisco Nexus 7000 you will quickly realise that the cost of Cisco’s 10GbE capable switch is really expensive. I found that a typically configured Nexus 7018 with a good number of 10GbE and some 1GbE was around GBP£500K / USD$800K. Admittedly, this was a fully loaded model but forms the basis for a cost analysis against our existing Cat6500 choices. Frankly, I couldn’t convince anyone that this was a good idea.
Sure, the Nexus 7000 is good product (not a great product in my opinion) and offers some 10GbE capability but the lack of features and high cost means that 10GbE is still not a part of our short term strategy. I wonder how many other people have a similar problem ?
Which Year was that ?
It seems that every year is the year of 10 Gigabit Ethernet.