Envelope theorem: Difference between revisions

From formulasearchengine
Jump to navigation Jump to search
 
en>A. Pichler
Line 1: Line 1:
Ed is what people call me and my wife doesn't like it at all. What me and my family love is doing ballet but I've been taking on new things recently. Her family lives in Ohio but her spouse wants them to move. Credit authorising is how he makes cash.<br><br>my page: good psychic ([http://help.ksu.edu.sa/node/65129 look at this site])
'''Weighted random early detection''' (WRED) is a queueing discipline for a [[network scheduler]] suited for [[Network congestion avoidance|congestion avoidance]].<ref>{{cite web |url=http://www.cisco.com/en/US/docs/ios/12_2/qos/configuration/guide/qcfconav_ps1835_TSD_Products_Configuration_Guide_Chapter.html |title=Congestion Avoidance Overview |publisher=Cisco |accessdate=2012-05-10}}</ref> It is an extension to [[random early detection]] (RED) where a single queue may have several different queue thresholds. Each queue threshold is associated to a particular [[Traffic_shaping#Traffic_classification|traffic class]].
 
For example, a queue may have lower thresholds for lower priority packet. A queue buildup will cause the lower priority packets to be dropped, hence protecting the higher priority [[network packet|packets]] in the same queue. In this way [[quality of service]] prioritization is made possible for important packets from a pool of packets using the same buffer.<ref>{{cite web |url=http://www.cisco.com/en/US/docs/ios/11_2/feature/guide/wred_gs.html |title=Weighted Random Early Detection (WRED) |publisher=Cisco |accessdate=2011-05-27}}</ref>
 
It is more likely that standard traffic will be dropped instead of higher prioritized traffic.
 
== Restrictions ==
On Cisco switches WRED is restricted to
* TCP/IP traffic. Only this kind of traffic indicates congestion to the sender to enable a reduction of the transmission rate.
Non-IP traffic will be dropped more often than TCP/IP traffic because it is treated with the lowest possible precedence.
 
== Functional Description ==
WRED proceeds in this order when a packet arrives:
* Calculation of the average queue size.
* The arriving packet is queued only if the average queue size is below the minimum queue threshold.
* Depending on the packet drop probability the packet is either dropped or queued if the average queue size is between the minimum and maximum queue threshold.
* The packet is automatically dropped if the average queue size is greater than the maximum threshold.
 
=== Calculation of average queue size ===
The average queue size depends on the previous average as well as the current size of the queue. The calculation formula is given below:
 
<math> avg= o*(1-2^{-n}) + c*(2^{-n})\,\!</math>
 
where <math>n</math> is the user-configurable exponential weight factor, <math>o</math> is the old average and <math>c</math> is the current queue length. The previous average will be more important for high values of <math>n</math>. Peaks and Lows in queue length will be smoothed by a high value. Low values of n allows the average queue size to stay close to the current queue size.
 
==References==
{{Reflist}}
 
[[Category:Network performance]]
 
 
{{Compu-network-stub}}
 
[[da:Undgåelse af datanet-trafikforstoppelse#RED og WRED]]

Revision as of 16:22, 14 December 2013

Weighted random early detection (WRED) is a queueing discipline for a network scheduler suited for congestion avoidance.[1] It is an extension to random early detection (RED) where a single queue may have several different queue thresholds. Each queue threshold is associated to a particular traffic class.

For example, a queue may have lower thresholds for lower priority packet. A queue buildup will cause the lower priority packets to be dropped, hence protecting the higher priority packets in the same queue. In this way quality of service prioritization is made possible for important packets from a pool of packets using the same buffer.[2]

It is more likely that standard traffic will be dropped instead of higher prioritized traffic.

Restrictions

On Cisco switches WRED is restricted to

  • TCP/IP traffic. Only this kind of traffic indicates congestion to the sender to enable a reduction of the transmission rate.

Non-IP traffic will be dropped more often than TCP/IP traffic because it is treated with the lowest possible precedence.

Functional Description

WRED proceeds in this order when a packet arrives:

  • Calculation of the average queue size.
  • The arriving packet is queued only if the average queue size is below the minimum queue threshold.
  • Depending on the packet drop probability the packet is either dropped or queued if the average queue size is between the minimum and maximum queue threshold.
  • The packet is automatically dropped if the average queue size is greater than the maximum threshold.

Calculation of average queue size

The average queue size depends on the previous average as well as the current size of the queue. The calculation formula is given below:

avg=o*(12n)+c*(2n)

where n is the user-configurable exponential weight factor, o is the old average and c is the current queue length. The previous average will be more important for high values of n. Peaks and Lows in queue length will be smoothed by a high value. Low values of n allows the average queue size to stay close to the current queue size.

References

43 year old Petroleum Engineer Harry from Deep River, usually spends time with hobbies and interests like renting movies, property developers in singapore new condominium and vehicle racing. Constantly enjoys going to destinations like Camino Real de Tierra Adentro.


Selecting the right web hosting service is very important. The last thing you wish to do is get a website published with a hosting service (after finding out to make use of that hosting service), and then be dissatisfied with the service and have to mess around with transferring your website to an additional hosting service.



I'm a delighted HostGator client. I make use of both HostGator and Bluehost.

I'll start with among the most important factors to consider: Price

HostGator has several pricing plans. They are as follows (since the date this post was released):.

Hatchling Strategy: as reduced as $4.95 per month with a 3 year commitment. On this plan you can host one website.
Infant Strategy: as reduced as $7.95 per month with a 3 year dedication. On this plan you can host an unrestricted number of websites.
Company Strategy: as reduced as $12.95 per month with 3 year dedication.

You don't need to commit for 3 years. With shorter term dedications, you'll pay somewhat even more per month.

You can likewise get your very own specialized server if this is something you such as to have.

Limitless variety of sites.

I would not consider a hosting service that didn't let me host an unrestricted variety of internet sites for one monthly price under $10. I have numerous sites and I like the adaptability of being able to construct more sites at no extra expense (other than for registering the domain).

If you choose for the Infant Strategy (this is the plan I have) or Company Strategy, you can host as many internet sites on as lots of domain names as you like. This is where making use of a hosting service like HostGator can save you an excellent offer of cash in the long run vs. using a website contractor or having a website designer host your internet sites. When you utilize a website builder or have a website designer host your website, you'll typically pay additional for each extra internet site (or each added set of internet sites).

The drawback obviously, is you should manage your own hosting. However, thankfully, this isn't really tough with the simple CPanel and technical support.

Domain registration.

You can quickly register domain with HostGator. You should pay for each domain. REMEMBER to set your domain on auto-renew (and that your billing information is set up to auto-pay) so your domain registration doesn't lapse. Nothing can be even worse than developing a great site and afterwards to lose it all since you forgot to renew your domain. It's possible then that another person registers your domain and you cannot get it again. That might be disastrous.

All HostGator prepares offer unrestricted bandwidth.

This is good and you must need this with any website hosting service. I would not consider making use of a hosting service that didn't provide unrestricted bandwidth.

User friendly CPanel Dashboard.

You manage your websites with HostGator in a dash panel described as a CPanel. The CPanel is a user friendly interface to handle your websites and domains.

Easy website installment.

I particularly need with any hosting service that I make use of can install WordPress with practically a single click or a series of basic clicks. HostGator provides Fantastico De Luxe and QuickInstall options for easily installing WordPress and numerous various other scripts to develop your site (i.e. Joomla and others).

Access to 4,500 website design templates.

For any internet designer, this is substantial. This is a wonderful means to build internet sites cheaply for clients. You can check out these templates for yourself on the HostGator site without having to sign up.

Free website builders.

With an account, you can easily construct a site with one of 2 website builders you get access to. The 2 site builders are:.

In case you loved this information and you wish to receive details relating to www.hostgator1centcoupon.info - https://banyetes.paeria.cat/?option=com_k2&view=itemlist&task=user&id=34102 - please visit our webpage. Trendy Website Home builder, and.
Website Studio website contractor.

Note, you can only use the website contractors for one website on your account. What this indicates is if you get an account where you can host endless domains, you can just build one website with a website builder.

E-mail accounts.

You get unrestricted POP3 e-mail accounts with SMTP. Having email accounts on your custom-made domain names is more professional than a gmail or hotmail email account.

45 day refund assure.

You can get your money back if you cancel your account within 45 days if HostGator isn't for you.

Video tutorials.

HostGator offers you access to various video tutorials that step you through many processes.

Client support.

The operators for technical support know a lot about working in HostGator. If you have a concern about personalizing a WordPress style, HostGator won't help you (I found this to be the case with Bluehost.

1 Criticism of HostGator.

I had to call HostGator to verify my account upon opening it. This didn't take long, but it was an additional step. I would have chosen just to sign up and get going without needing to call them for confirmation.

da:Undgåelse af datanet-trafikforstoppelse#RED og WRED