Saturday, October 25, 2008

Administrative Distance

Default Distance Value Table

This table lists the administrative distance default values of the protocols that Cisco supports:

Route Source

Default Distance Values

Connected interface

0

Static route

1

Enhanced Interior Gateway Routing Protocol (EIGRP) summary route

5

External Border Gateway Protocol (BGP)

20

Internal EIGRP

90

IGRP

100

OSPF

110

Intermediate System-to-Intermediate System (IS-IS)

115

Routing Information Protocol (RIP)

120

Exterior Gateway Protocol (EGP)

140

On Demand Routing (ODR)

160

External EIGRP

170

Internal BGP

200

Unknown*

255

One Day at a time - What I think

I feel great when I sit on my table for studies with a cup of coffee or tea and immersing myself in network topologies. Nothing can beat this feeling and at the end of the day; strongly feel this is what I want to do in my life. Practicing lab scenarios; facing trouble in solving it with my small brain cells and nailing it with all troubleshooting skills whether I have it or not :).

I hope to continue on this path for next 10 years and get all security/ networking concepts in my brain.

As of now I do not have a single certification but hope God show me a path where I am forced to do all these certification without disturbing my mind peace.

Sunday, October 12, 2008

"Quarter-life Crisis."

Got this in personal email box long time back...........Sometimes good to read such stuff to realize that "Life is not a race but a journey to be savored at each step" :)
" Quarter - life Crisis...! "

It is when you stop going along with the crowd and start realizing that there are many things about yourself that you didn't know and may not like. You start feeling insecure and wonder where you will be in a year or two, but then get scared because you barely know where you are now.

You start realizing that people are selfish and that, maybe, those friends that you thought you were so close to aren't exactly the greatest people you have ever met, and the people you have lost touch with are some of the most important ones. What you don't recognize is that they are realizing that too, and aren't really cold, catty, mean or insincere, but that they are as confused as you.

You look at your job... and it is not even close to what you thought you would be doing, or maybe you are looking for a job and realizing that you are going to have to start at the bottom and that scares you.

Your opinions have gotten stronger. You see what others are doing and find yourself judging more than usual because suddenly you realize that you have certain boundaries in your life and are constantly adding things to your list of what is acceptable and what isn't. One minute, you are insecure and then the next, secure.

You laugh and cry with the greatest force of your life. You feel alone and scared and confused. Suddenly, change is the enemy and you try and cling on to the past with dear life, but soon realize that the past is drifting further and further away, and there is nothing to do but stay where you are or move forward.

You get your heart broken and wonder how someone you loved could do such damage to you. Or you lie in bed and wonder why you can't meet anyone
decent enough that you want to get to know better. Or maybe you love someone but love someone else too and cannot figure out why you're doing this because you know that you aren't a bad person.  Getting wasted and acting like an idiot starts to look pathetic. You go through the same emotions and questions over and over, and talk with your friends about the same topics because you cannot seem to make a decision. You worry about loans, money, the future and making a life for yourself... and while winning the race would be great, right now you'd just like to be a contender!

What you may not realize is that every one reading this relates to it. We are in our best of times and our worst of times, trying as hard as we can to figure this whole thing out.

We call it the "Quarter-life Crisis."

FATE DETERMINES WHO COMES INTO OUR LIVES.....HEART DETERMINES WHO STAYS

Obstacles are placed across our path in life not to be boggled at , but to be SURMOUNTED

Friday, October 10, 2008

Wednesday, October 8, 2008

VOIP per call bandwidth

Voice Over IP - Per Call Bandwidth Consumption

for VOIP CALCULATOR click Here

Codec Information

Bandwidth Calculations

Codec & Bit Rate (Kbps)

Codec Sample Size (Bytes)

Codec Sample Interval (ms)

Mean Opinion Score (MOS)

Voice Payload Size (Bytes)

Voice Payload Size (ms)

Packets Per Second (PPS)

Bandwidth MP or FRF.12 (Kbps)

Bandwidth w/cRTP MP or FRF.12 (Kbps)

Bandwidth Ethernet (Kbps)

G.711 (64 Kbps)

80 Bytes

10 ms

4.1

160 Bytes

20 ms

50

82.8 Kbps

67.6 Kbps

87.2 Kbps

G.729 (8 Kbps)

10 Bytes

10 ms

3.92

20 Bytes

20 ms

50

26.8 Kbps

11.6 Kbps

31.2 Kbps

G.723.1 (6.3 Kbps)

24 Bytes

30 ms

3.9

24 Bytes

30 ms

34

18.9 Kbps

8.8 Kbps

21.9 Kbps

G.723.1 (5.3 Kbps)

20 Bytes

30 ms

3.8

20 Bytes

30 ms

34

17.9 Kbps

7.7 Kbps

20.8 Kbps

G.726 (32 Kbps)

20 Bytes

5 ms

3.85

80 Bytes

20 ms

50

50.8 Kbps

35.6 Kbps

55.2 Kbps

G.726 (24 Kbps)

15 Bytes

5 ms


60 Bytes

20 ms

50

42.8 Kbps

27.6 Kbps

47.2 Kbps

G.728 (16 Kbps)

10 Bytes

5 ms

3.61

60 Bytes

30 ms

34

28.5 Kbps

18.4 Kbps

31.5 Kbps

Explanation of Terms

Codec Bit Rate (Kbps)

Based on the codec, this is the number of bits per second that need to be transmitted to deliver a voice call. (codec bit rate = codec sample size / codec sample interval).

Codec Sample Size (Bytes)

Based on the codec, this is the number of bytes captured by the Digital Signal Processor (DSP) at each codec sample interval. For example, the G.729 coder operates on sample intervals of 10 ms, corresponding to 10 bytes (80 bits) per sample at a bit rate of 8 Kbps. (codec bit rate = codec sample size / codec sample interval).

Codec Sample Interval (ms)

This is the sample interval at which the codec operates. For example, the G.729 coder operates on sample intervals of 10 ms, corresponding to 10 bytes (80 bits) per sample at a bit rate of 8 Kbps. (codec bit rate = codec sample size / codec sample interval).

MOS

MOS is a system of grading the voice quality of telephone connections. With MOS, a wide range of listeners judge the quality of a voice sample on a scale of one (bad) to five (excellent). The scores are averaged to provide the MOS for the codec.

Voice Payload Size (Bytes)

The voice payload size represents the number of bytes (or bits) that are filled into a packet. The voice payload size must be a multiple of the codec sample size. For example, G.729 packets can use 10, 20, 30, 40, 50, or 60 bytes of voice payload size.

Voice Payload Size (ms)

The voice payload size can also be represented in terms of the codec samples. For example, a G.729 voice payload size of 20 ms (two 10 ms codec samples) represents a voice payload of 20 bytes [ (20 bytes * 8) / (20 ms) = 8 Kbps ]

PPS

PPS represents the number of packets that need to be transmitted every second in order to deliver the codec bit rate. For example, for a G.729 call with voice payload size per packet of 20 bytes (160 bits), 50 packets need to be transmitted every second [50 pps = (8 Kbps) / (160 bits per packet) ]

Bandwidth Calculation Formulas

The following calculations are used:

  • Total packet size = (L2 header: MP or FRF.12 or Ethernet) + (IP/UDP/RTP header) + (voice payload size)
  • PPS = (codec bit rate) / (voice payload size)
  • Bandwidth = total packet size * PPS