Fibre Channel Naming Should Match its Performance

Industry Brief

The network technology named "10GbE" means throughput is 10Gb/s, and if

you're like most people, you would naturally believe the network called "32GFC,"

means throughput is 32Gb/s. The reality is the name matches the speed for

Ethernet, but surprisingly not for Fibre Channel. The speed of the network is

significantly less than the names for each generation of Fibre Channel.

If you care to know how many people were aware of this, how we got here, what

IT pros think should be done, and what the industry is going to do about it,

continue reading.

Who Knew Fibre Channel Names Don't Match Speed

3

After talking to several Fibre Channel

industry insiders, I discovered it's

common knowledge that actual Fibre

Channel speed doesn't match the

number in the name. The next step was

to measure awareness of the disparity

in the IT community. IT Brand Pulse

conducted an independent, non-

sponsored survey of 200 IT pros, and

not surprisingly, the vast majority

expected the name "32GFC" meant the

speed of Fibre Channel is 32Gbps.

How This Happened: Speed-Based Naming Is A Baudy Affair

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Turns out since the technology was introduced, Fibre Channel

went through periods where it was named after its baud rate,

followed by the current time frame where Fibre Channel

naming is "generation-based."

After the dial-up modem industry faded away, Fibre Channel

alone carried the flag of using baud rate as their reference

point for naming. What should be used to identify each new

generation of Fibre Channel, is a well established convention:

half-duplex throughput in Gb/s. You can arrive at that number

by multiplying the baud rate by a factor for encoding overhead.

Using Gbaud for naming is, best-case, confusing and

somewhat irrelevant. Worst case, it is deceptive. (Watch

this video for an explanation of how Ethernet and Fibre

Channel performance are measured, and where the GBaud

specification fits.)

During the time this 2008 road map was published, the product name was based on

the Line rate (Gbaud) specification. However, if you multiply Gbaud x the encoding

overhead factor, you arrive at the effective throughput number (and name) which is

apples-to apples with Ethernet naming. That means 1Gb FC was actually 850Mb

FC, and the technology entered the gigabit age at 2Gb FC, which is actually 1.7Gb

FC. Clearly the "Product" specifications in the chart are confusing or deceptive.

Generation-Based Naming

5

At 8GFC, the naming in the generation-based Fibre Channel

road maps was changed to 1GFC, 2GFC, 4GFC, etc. Oddly,

the entire SAN industry referred to the technology in terms of

Gbps, yet there was no mention of that specification in the

speed road map.

The intention isn't clear with this approach, but the results

seem very clear.

Result #1: the vast majority of people interpret the names of

each generation of Fibre Channel as network throughput,

when they are not.

Result #2: the market makes the easy translation to

throughput (the higher number), and voila!, 16GFC becomes

16Gb FC.

Result #3: the industry has plausible deniability, but many

customers are misled.

6

It is common for vendors and

industry organizations to drop the

Gen 5 / Gen 6 naming convention

and misrepresent the technology

as 8Gb, 16Gb FC, etc.

It Matters to the IT Community

7

Next, IT Brand Pulse asked IT

professionals what they thought of

this dilemma. About two-thirds of

the respondents answered, "Not a

big deal, but the Fibre Channel

industry should update their road

map..." However, the industry

should take notice that almost a

quarter of the respondents think

"This is a big deal, we have been

deceived for a long time..." Over 80% of IT professionals surveyed said the FC road map

should be fixed.

The Gap is Growing

8

This was not much of an issue is when the naming logic was "close-enough" at 1Gb FC

and the difference between name and speed was .15Gbps. But at 32GFC, the gap is

almost 5Gbps, and it's snow-balling.

On behalf of IT community, I'm calling on the Fibre Channel industry to update their road

map so the naming accurately reflects the speed of the network in Gb/s....just like we're

used to with Ethernet. To hold us over until then, IT Brand Pulse has created the Official

Fibre Channel Road Map Translator.

As you can on the next slide, we have taken the liberty of renaming each generation and

re-introduced "Gb" in the name. By looking at the name, users can easily make an apple-

to-apples comparison with Ethernet. I've also listed throughput in Gb/s, the well-

established convention for network speeds. By using this road map, you will no longer

need to convert from MB/s full-duplex to Gb/s half-duplex, in order to get the most widely

used specification for network performance.

FCIA Road Map

Gross bit rate (Line Rate in FCIA Road Map)

Encoding Encoding Overhead

Factor

Effective bit rate Gross bit rate x overhead

factor

IT Brand Pulse Road Map

1GFC 1.0625Gb/sec 8b/10b .8 .85Gb/sec 850Mb FC

2GFC 2.12Gb/sec 8b/10b .8 1.7Gb/sec 1.7Gb FC

4GFC 4.25Gb/sec 8b/10b .8 3.4Gb/sec 3.5Gb FC

8GFC 8.5Gb/sec 8b/10b .8 6.8Gb/sec 7Gb FC

16GFC 14.025Gb/sec 64b/66b .9696 13.6Gb/sec 14Gb FC

32GFC 28.05Gb/s 64b/66b .9696 27.2Gb/sec 27Gb FC

64GFC 56.1 Gb/s 64b/66b .9696 54.4Gb/sec 54Gb FC

128GFC 112.2 Gb/s 64b/66b .9696 108.8Gb/s 108Gb FC

256GFC 224.4 Gb/s 64b/66b .9696 217.6Gb/s 218Gb FC

Official Fibre Channel Road Map Translator

Translation Name that does not

match actual speed

Name that matches

actual speed Exact speed

In Industry Organizations We Trust

10

The networking industry is a highly-competitive arena with tens of billions of

dollars on the table. In spite of the high stakes and intense competition, the

industry organizations that document standards and specifications

have earned our trust by publishing accurate information about Fibre Channel,

Ethernet and InfiniBand. Traditionally, it's been left to vendor product

marketing teams to add spin to the basic specifications in the industry road

maps

A shout-out to the Fibre Channel industry to take a serious look at this. If not,

we look forward to getting lots of views on the Official Fibre Channel Road

Map Translatorin the months and years ahead!