Bandwidth as a Link Metric (routing point of view)

mq15 · 07-01-2009, 10:57 PM

Hello friends.
In the following paragraph Bandwidth is discussed as a link metric for routing protocols, but I little understand it. Please get me explain this.
Regards.

Quote:

Bandwidth is not additive, it is good when high, bad when low; thus in order to treat it as additive, it must be properly mapped. Consider, for example, a preference for a route that maximizes the minimum bandwidth link on the route, and then prefers a route with the fewest links of each bandwidth from the lowest. If links may be of three discrete bandwidths, "high", "medium" and low", this preference can be achieved, on the assumption that no route will have more than 10 links, with metric values of 1, 10 and 100 for the three bandwidths. If routes can have more than 10 links, the range of metrics must be increased; this indicates a preference for a wide "dynamic range" of link metric values.

stress_junkie · 07-02-2009, 04:26 PM

Nobody has responded yet so I'll offer an opinion.

I believe that anyone would find that paragraph difficult to understand. It seems to me that the author has used writing techniques designed to confuse the reader and obfuscate the meaning of the text. Techniques such as juxtaposing words that mean the opposite of each other, as in the expression "...maximizes the minimum..." and using other similar writing elements eventually overwhelms the reader with too much mental work to effectively understand the meaning of the text.

It seems that the person who wrote this is either a very poor writer or is intentionally trying to "baffle the readers with bullshit" as is often done by people in professional positions when they don't know what they are talking about. I'd say that whoever wrote that paragraph is attempting sound very knowledgeable and impress people who do not understand the subject. The concepts that are being presented in such a torturous manner are, in fact, very simple. The writer is simply talking about configuring a network route to achieve the greatest performance at the least cost of resources. However when you read the paragraph you come away confused and convinced that the subject matter must be very advanced and complex. It is neither. I suggest that the writer was very confused and unable to express themselves clearly.

Or, I could be wrong.

mq15 · 07-03-2009, 10:11 AM

Thank you stress_junkie for taking interest. You may be right. Let us wait some more time for someone's help and guidance..

CmdoColin · 07-06-2009, 10:34 AM

Metric is a cost used to select a route, traffic will be passed down the lowest cost route.

So I'd config:

route add -net 192.168.1.0 netmask 255.255.255.0 gw 10.0.0.1 metric 1
route add -net 192.168.1.0 netmask 255.255.255.0 gw 10.0.0.2 metric 10

When gateway 10.0.0.1 is available, it will use that, when it isn't it will use the higher cost metric of 10, and get passed to the 10.0.0.2.

Re-read that paragraph and it makes sense then.

mq15 · 07-28-2009, 01:21 PM

Thanks. You really cleared the point.