Solved

Why last ARPANET approach for setting link weights abandoned in the Internet

Posted on 2010-08-24
7
61 Views
Last Modified: 2016-05-28
 In the ARPANET, link weights used to change dynamically. They represented the average delay over a period of 10 seconds. Whenever a link delay changed considerably, the router would issue a routing update to report the link weight change. Why was this approach for setting link weights abandoned in the Internet?
0
Comment
Question by:mrkidhiworld
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 3
  • 2
7 Comments
 
LVL 4

Accepted Solution

by:
DeadRatRacer earned 334 total points
ID: 33549510
The current routing protocol, BGP does still use a metric weighting system that is affected by link speed and other factors like link stability.

Each AS participating in Internet routing sort of keeps its own view of the world and every route possible relative to itself, based on information from its neighbors that keep their own view based on ITS neighbors and so on.

For issues of scaling - directly notifying a backbone router in Brazil that a link in Nebraska many hops away is running a bit slow would not serve any meaningful purpose.

Out of curiosity, which specific version of ARPANET routing are you referring to? The system evolved over time and adjustments/changes happened many times in the evolutions that lead to the modern internet.
0
 
LVL 4

Assisted Solution

by:DeadRatRacer
DeadRatRacer earned 334 total points
ID: 33549641
Small excerpt taken from
http://www.isoc.org/internet/history/brief.shtml


The increase in the size of the Internet also challenged the capabilities of the routers. Originally, there was a single distributed algorithm for routing that was implemented uniformly by all the routers in the Internet. As the number of networks in the Internet exploded, this initial design could not expand as necessary, so it was replaced by a hierarchical model of routing, with an Interior Gateway Protocol (IGP) used inside each region of the Internet, and an Exterior Gateway Protocol (EGP) used to tie the regions together. This design permitted different regions to use a different IGP, so that different requirements for cost, rapid reconfiguration, robustness and scale could be accommodated. Not only the routing algorithm, but the size of the addressing tables, stressed the capacity of the routers. New approaches for address aggregation, in particular classless inter-domain routing (CIDR), have recently been introduced to control the size of router tables.
0
 
LVL 4

Expert Comment

by:DeadRatRacer
ID: 33549651
And I neglected to mention before that alot of the metric re-jiggering is done by the network operators and less by the protocol itself
0
What is SQL Server and how does it work?

The purpose of this paper is to provide you background on SQL Server. It’s your self-study guide for learning fundamentals. It includes both the history of SQL and its technical basics. Concepts and definitions will form the solid foundation of your future DBA expertise.

 
LVL 28

Assisted Solution

by:mikebernhardt
mikebernhardt earned 166 total points
ID: 33559621
BGP does not, and has never done, any automatic changes due to link speeds or other dynamic factors! A link is either up or it isn't. After that everything is determined by policies that have been configured by humans.

Dynamic changes are a function of IGPs like OSPF or EIGRP. EIGRP especially has the capability to change metrics based on factors like congestion (but no one uses it). The Internet is far too big, and therefore has far too many links, for tens of thousands of routers to be constantly updating routing tables due to metric changes somewhere. The whole Internet would come to a halt!
0
 

Expert Comment

by:EE_AutoDeleter
ID: 41620661
I've requested that this question be deleted for the following reason:

                           
No comment has been added to this question in more than 21 days, so it is now classified as abandoned and is now flagged for deletion.


If there is a valid solution, please OBJECT and indicate the comments that are, or would otherwise lead to, a solution.


Use the specific format http:#axxxxxxxx for comment ID(s).


Also, please don't object simply because the author did not respond to your comment. While we understand this is frustrating, unfortunately we cannot force the author to return to the question. Unless you feel you have presented a valid, verifiable solution we'll simply delete the question.


Experts-Exchange Auto Deleter
0

Featured Post

Independent Software Vendors: We Want Your Opinion

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Understanding FTPS File transfer is a common requirement in most Enterprises. While there are numerous ways to get a file from Point A to Point B over a network, perhaps the most common method still in use is FTP – File Transfer Protocol. FTP is …
Please see preceding article here: http://www.experts-exchange.com/Networking/Operating_Systems/A_11209-Root-Bridge-Election.html Figure 1 After Root Bridge has been elected, then what?..... Let's start by defining a Root Port in la…
Viewers will learn how to properly install and use Secure Shell (SSH) to work on projects or homework remotely. Download Secure Shell: Follow basic installation instructions: Open Secure Shell and use "Quick Connect" to enter credentials includi…
In this brief tutorial Pawel from AdRem Software explains how you can quickly find out which services are running on your network, or what are the IP addresses of servers responsible for each service. Software used is freeware NetCrunch Tools (https…

717 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question