Friday, March 23, 2012

Myth vs. Reality: 10 Gigabit Ethernet

An extract of an interesting article By Michael Brandenburg, Technical Editor Dell.

Although 40 and 100 Gigabit Ethernet represent the industry's cutting edge, the vast
majority of enterprises are still in the midst of a transition from Gigabit Ethernet to 10
Gigabit Ethernet (GbE) in their networks. While 10 GbE has been broadly available for
years, it is still new to most network engineers. With that in mind, we are busting some of the most common myths surrounding the technology in this 10 GbE edition of myth versus reality.

Myth: Deploying 10 Gigabit Ethernet is too expensive.

Reality: While the price per port of 10 GbE is still higher than Gigabit Ethernet, the gap
between the two is narrowing. In high-traffic areas of the network, it might actually be more cost effective to use a single 10 GbE port rather than ten Gigabit links to achieve the same level of bandwidth and performance.

What may really work: Mike Spanbauer, principal analyst for enterprise networking and
data centre technology at Current Analysis, suggests that enterprises evaluate the entire
cost of an access port, including power consumption and port density. In data centres where power, cooling and physical space are a premium, 10 GbE may actually be the more cost effective option.

Myth: 10 Gigabit Ethernet only works on expensive optical cables and transceivers.

Reality: Engineers have a range of cabling options for 10 GbE, with more on the way. While optical is the primary choice for long-range links between switches in the data centre, enterprises can choose lower-cost optical cabling or twinax copper cabling for shorter range or to interconnect within the server rack. Also, many server and switch vendors are preparing to launch products with 10GBase-T, which will offer the convenience of the more common twisted pair cabling with RJ45 connectors for distances up to 100 meters.

What may really work: Cabling data centre networks can be an expensive, time consuming
proposition, so data centre managers should look into all of the available media
choices to maximize the life span of the physical network. Likewise, many data centre
managers prefer to standardize on a single, small form-factor pluggable (SPF+) transceiver module and cabling type, according to Spanbauer. So while a mix and match approach to cabling may offer short-term cost savings, installing fibre optic might offer greater investment protection to support 10 GbE and beyond.

Myth: Enterprises will have to completely rip and replace switches or do forklift upgrades to support 10 Gigabit Ethernet.

Reality: Many enterprises will discover that the modular switches running Gigabit Ethernet in their networks are capable of supporting 10 GbE line cards. Also, many new 10 GbE fixed configuration switches fit into the same footprint as existing, racked Gigabit Ethernet switches.

What may really work: The need for the additional bandwidth that comes with 10 GbE
may quickly spread beyond the data centre. A number of 802.11n wireless access points
could fill a Gigabit Ethernet uplink, necessitating 10 GbE links to aggregate the wireless LAN traffic, Spanbauer said. A network manager should consider 10 Gigabit options throughout the entire enterprise network.

Gigabit Ethernet uses all 4 pairs so requires the full 4 pair (8 conductor) cross configuration (shown above).