00:04

Okay, guys, don't be scared. I go away and I come back. And there's a scary looking formula on the on the board. It's not hard, and I will simplify this for you.

00:14

So, yes, J. R. P uses feasible distance

00:19

as this metric and what is feasible distance to find out. Well feasible distance is defined as

00:26

well defined in this formula. So K one into bandwidth

00:30

and I would swim. What K is

00:32

plaice skate you into band with over 2 56 minus the load on the link

00:37

or the current traffic on the link

00:40

plus K three into delay The delay of the link? The delay a packet will incur while transporting that link

00:48

multiplied by care five

00:50

divided by care for into reliability, that reliability of the link being how many times in the past hour sold this ring cast failed and come back up

01:00

mount of the whole thing multiplied or scaled up two by 2 56

01:07

the band with for AARP is actually tend to the power seven,

01:12

divided by the Louis bandwidth between your current position and the destination between the source and the destination.

01:22

The AARP delay is defined as the sum of all delays between source and destination in units off tens off microseconds, though, this little U stands for microbe.

01:34

So whatever the total delays, we will simply divided by 10 because it has to be in units of tens of microseconds

01:42

by default. These K values

01:46

K one and K three are one and kid 24 and five are set to defy zero by default.

01:53

If Kay 50 then you ignore this half of the formula, which is weird. It doesn't work like that in mathematics, but it's discourse for a call. Cisco's rules.

02:04

So if K 50 you ignored this half of the formula,

02:07

kid values range between zero and 255

02:12

Now what exactly is a K value?

02:14

Here is nothing but a weight. It's a *** that you can turn so by default. Okay, one and K three are one, and everything else is set to zero.

02:23

When if I wanted Ta Joppy to also consider the load of the link

02:28

while making its calculations to find which the best route is with the Louis feasible distance, then I might want to increase

02:36

the K to value from zero to maybe five. I wanted to consider the load on the link a little bit more than bandwidth, or I wanted it to consider the loan on the link. Ah, lot more than band with. I can set this to

02:49

255 K to allude to 255

02:52

What if I want a job for you to consider only the delay of the link and not the band with? Well, I can set k 1 to 0 all of the K values to zero, and I can set K three, which is multiplied by delay to a high number or just one.

03:07

If I want your Joppy to only consider bandwith while making his calculation, I can set all other K values to zero, and I can just set k one to the number one or a higher value.

03:20

Now, as I said, T one and K three are won by default and every other K value is zero. Let's see what happens to our formula

03:30

once we set the K values

03:35

it's okay to four and five are zero.

03:38

care to a 00 into something a zero so this goes to zero

03:46

Okay, this whole portion goes to zero. If k 50 we ignore this side of the formula. So the formula produces down to K. One is one.

03:55

Anyone? Anything multiplied by one is the same number.

04:03

que trees one anything multiplied by one again is one

04:09

delay whole thing multiplied by

04:12

2 56 The fish feasible distance formula reduces down to bandwidth plus delay if default values are being used

04:23

multiplied by 2 56 scaled up by 2 56

04:26

This concludes the metric portion or the feasibility feasible distance portion of the lecture.