6 of the Best Free Linux Web Caches

Hypertext Transfer Protocol (HTTP) is considered to be the fundamental protocol of the web. This simple request/response protocol is used for distributed, collaborative, hypermedia information systems. The web consumes a large portion of internet traffic.

With HTTP, a client makes a request for a resource to a server, and the server delivers messages with additional content such as images, style sheets and JavaScripts. HTTP dictates how these messages are displayed and transmitted, and how web servers and browsers should respond to various commands.

The developers of the HTTP protocol realised at an early stage that there was going to be rapid growth in web traffic. This continues to be the case. For example between 2000-2010, internet usage increased by more than 400%, much of which was accounted for by web traffic. With the anticipated insatiable demand for the web, developers added powerful caching primitives.

It is a demonstrable fact that the internet has changed individuals' expectations of the speed of content delivery. The same individuals who used to be content to wait a couple of days for a letter to be received now expect emails to be delivered within a matter of seconds. The same applies to web browsing. A slow-loading website is a recipe for online disaster even if the site is informative, well structured and organised. When it comes to interactive web usage, what really matters is median latency.

Web caches have become a vital mechanism for optimising the amount of data that is delivered in a given period of time. Good web caches also help to minimise latency, serving pages as quickly as possible. This helps to prevent the end user from becoming impatient having to wait for content to be delivered. Web caches optimise the data flow between client and server. They also help to converse bandwidth by caching frequently-delivered content. If you need to reduce server load and improve delivery speed of your content, it is definitely worth exploring the benefits offered by web cache software.

This type of software is primarily used by Internet Service Providers (ISPs), backbone providers, large intranets and enterprises. Web caches are very versatile, and are used in a number of different systems such as search engines, web proxies, and forward caches.

In this article, we feature the best open source software that caches web content, optimising and cleaning the network traffic.

To provide an insight into the open source software that is available, we have compiled a list of 6 of our favorite web cache software. Hopefully, there will be something of interest here for anyone who needs to reduce bandwidth usage, improve latency, and minimise server load.

So, let's explore the 6 web caches at hand. For each application we have compiled its own portal page, a full description with an in-depth analysis of its features, together with links to relevant resources and reviews.

Web Caches
nginx	Very powerful and efficient web server and reverse proxy
Varnish Cache	Web accelerator written with performance and flexibility in mind
Squid	High-performance proxy caching server and web cache daemon
Traffic Server	High-performance building block for cloud services
Polipo	Fast and lightweight caching web proxy
eAccelerator	PHP accelerator and optimizer derived from the MMCache extension

Egypt Call Centres

Xceed (Egypt)

Address:
Km 28 Pyramids Smart Village, Cairo/Alex Road, Egypt
Tel: +202-7763000
Fax: +202-7763001

Description:
Xceed Contact Center is the largest and most sophisticated Contact Center in the southern Mediterranean region. Xceed is an Egyptian-based provider of integrated customer contact solutions to commercial and government clients worldwide.

URL: http://www.xceedcc.com

Job Openings: View company profile for existing job opportunities.

Send your C.V to :  asc@xceedcc.com

you must mention the position that you are applying for in the Title.






Teleperformance (Egypt)

Address:
Above Shoubra TunnelWerash El-Telefounat St.
Ard El-Sabeel
Post Office Building
Shoubra, Cairo
Egypt
Tel: + (20) 225948800


Description:
Established in 2007, Teleperformance Egypt was the first multinational contact center company to open in Egypt performing all contact center services, including customer care, customer service, acquisition, technical support and debt collection. We provide outsourcing services in Egypt, the Middle East and Africa, and offshore markets serving North America, the UK and regions of Europe.

URL: http://www.teleperformance.com


Send your C.V to :-
                                    careers@teleperformance.com.eg
                                    iammar@teleperformance.com.eg






Stream Contact center

Stream(Egypt)

Address:
7 Abdel Hamid El Erayan Street
Motamayez Zone
6th of October
Cairo Egypt
Tel: +20(0)225228078    

Description:
Stream Cairo is an excellent offshore solution center for multilingual services. The center benefits from Cairo's large and impressive labor pool with university students and high school graduates. Additionally various foreign universities and language institutions are located in the area. The center offers skills for a variety of multilingual services including all levels of customer care, technical support and revenue generation. Languages supported include Arabic, English and French, as well as Spanish, German and Italian.
With a solid infrastructure and excellent access services, combined with a high quality, college-educated workforce, Stream Cairo is a highly favorable location for offshore outsourcing.

URL: http://www.stream.com/index.php/locations/emea/cairo.html


send your C.V to : egypt.jobs@stream.com



Raya Contact center





Description:
Raya Contact Center (RCC) emerged to act as your right Business Process Outsourcing (BPO) partner, and offer you full scope of outsourced contact center services that boost customer interaction with greater cost efficiency and risk mitigation using flexible operational models that understand your business needs like in-sourcing, co-sourcing or outsourcing..

URL: http://www.rayacorp.com/ShowPage.aspx?menu=1&PID=886


send your C.V to :  offshore_vacancies@rayacorp.com
                                              habiba_fouad@rayacorp.com


 or you can apply through  the web site



Esnad Contact Center


BDO Esnad

Address:
68, El Marghany St., Heliopolis, Cairo, Egypt.
Tel.: +2 02-24134577
Fax: +2 02-24199077
Description:
BDO Esnad, the outsourcing arm of BDO Khaled & Co. which is one of the largest professional firms of auditors, accountants and advisors in Egypt practicing since 1985 with offices in Cairo and Alexandria serving numerous Multinational and Egyptian companies.


BDO Esnad was established to provide organizations with business process outsourcing (BPO) services that aim to drive long-term cost reductions while keeping a focus on continuous performance improvement. The BPO services provided to organizations across public and private sectors as well as onshore and offshore.

URL: http://www.esnad-bpo.com


send your C.V to : Go to this link and post your resume :http://www.esnad-bpo.com/


                                    http://www.esnad-bpo.com/recruitment.html




ECCO Contact Center


ECCO (Egypt)

Address:
Commercial Professional Association Bld.
29 Imtedad Ramsis St.
10th Floor

 +202 24 88 6000    
Description:
ECCO is one of the leading providers of a wide range of services, amongst which are Telesales, Telemarketing, Customer service, Order Management, and Fleet Management services.


URL: http://www.call-ecco.com/

send your C.V to :   hr@call-ecco.com



Etisal Contact center





Etisal (Egypt)

Address: Misr Al Syaha Tower, Abassia, Cairo, Egypt

Telephone:        +20 (2) 24887000
Fax:              +20 (2) 24887001
Description:
Etisal was founded in 2003 as a new member of the Riadaa Group to be the call center arm of the group. The “Riadaa” group was founded in 1998 as an operation and services company with 280 employees and grew into 4 companies.


URL: http://www.etisal-int.com


Send your C.V to : recruitment@etisal-int.com


Wasla Contact Center

Wasla(Egypt)

Address:
1. Head Office:Mostafa El Nahas St. Extension, 26A EL-Sheikh Mohamed Metwaly EL-Shaarawy St.
10th quarter Nasr City, Cairo, EGYPT.
P.O Box: 11528 , Postal Code: 11371

2. Abbassya Square, Tatbeqeyeen Tower, Cairo, Egypt
Description:
Wasla Contact Center established in the year 2003 to provide outsourced Contact Center Services to its clients in Egypt, the region, and globally. Wasla Contact Center is an information technology company majority owned by Paradise Capital Holding.

URL: http://www.wasla.com


send your C.V to : work@wasla.com



Teleconnect Contact Center




Address:
2 El Serag Towers, Atya Al Sawalhy St. Off Makram Ebaid St., Entrance No. 3
Nasr City, Cairo
Tel: 02-22736157, 010-1472492
Fax: 02-22736158
Description:
Teleconnect has a high caliber management team of agents qualified & working 24/7 to provide: Business Process Outsourcing (BPO) services & solutions (Consultancy / Database Services/ Back Office Solutions/ Management Online Business Cycles “CRM Application, Email & Fax”/ Recruitment & Training/ Payroll Services/ Inbound & Outbound "Telemarketing, Telesales, Tele-service & Technical Support").

URL: http://www.teleconnectcc.com/

Send your C.V to : hr@teleconnectcc.com




Ameco Tech



Address:
El Tatbiqeyeen Tower, , Floor 17, 16, 14
Abbasseya, Cairo
Tel: 02-24857848 begin_of_the_skype_highlighting              02-24857848    

Description:
Ameco Tech is a multinational corporation with American origins that was established in 2001 as the Pioneers of the communication business in the Middle East. Now we are looking for candidates who are able to understand our vision and want a chance to become a leader in this booming industry, and the opportunity for a long-term career.

URL: http://www.amecotech.com/

 Send your C.V : Go to the company and You will do interview on the spot


Ahlan Contact Center


Address: Maadi

Description:
hlan Contact Center   is an Egyptian provider of customer contact solutions to commercial clients & Business process outsourcing services capitalizing on its core competencies of efficient technologies, and highly skilled agents. Ahlan optimizes live inbound and outbound contact handling, as well as efficient business process management and support for its clients. We deliver the promise which is providing quality service to clients.

URL: http://www.ahlancontactcenter.co

Send your C.V to : career@ahlancontactcenter.com

Knockd, to secure your ports on Linux

Today, i’ll show you how to use knockd to improve the security of your linux server, the more common use that i’ve saw so far is: “i’d like to connect on port 22 (ssh) but i don’t want to leave to port open for everyone..and i’ve a dynamic IP”. In these cases you can close the ports and use knockd to knock on the ports of your Linux box and let you in.



knockd is a port-knock server. It listens to all traffic on an ethernet (or PPP) interface, looking for special “knock” sequences of port-hits. A client makes these port-hits by sending a TCP (or UDP) packet to a port on the server. This port need not be open — since knockd listens at the link-layer level, it sees all traffic even if it’s destined for a closed port. When the server detects a specific sequence of port-hits, it runs a command defined in its configuration file. This can be used to open up holes in a firewall for quick access.

Installation

Knockd it’s available in the repository of the major distributions, i’m using it on Ubuntu/Debian where the package it’s available.

Configuration

knockd reads all knock/event sets from a configuration file. Each knock/event begins with a title marker, in the form [name], where name is the name of the event that will appear in the log. A special marker, [options], is used to define global options.
Example:

[options]
        logfile = /var/log/knockd.log
 
[openSSH]
        sequence    = 700,800,900
        seq_timeout = 5
        command     = /sbin/iptables -I INPUT -s %IP% -p tcp --dport 22 -j ACCEPT
        tcpflags    = syn
 
[closeSSH]
        sequence    = 900,800,700
        seq_timeout = 5
        command     = /sbin/iptables -D INPUT -s %IP% -p tcp --dport 22 -j ACCEPT
        tcpflags    = syn

This example uses two knocks. The first will allow the knocker to access port 22 (SSH), and the second will close the port when the knocker is complete. As you can see, this could be useful if you run a very restrictive (DENY policy) firewall and would like to access it discreetly.
Example 2:

[options]
        logfile = /var/log/knockd.log
 
  [opencloseSSH]
        sequence      = 2222:udp,3333:tcp,4444:udp
        seq_timeout   = 15
        tcpflags      = syn,ack
        start_command = /usr/sbin/iptables -A INPUT -s %IP% -p tcp --syn --dport 22 -j ACCEPT
        cmd_timeout   = 10
        stop_command  = /usr/sbin/iptables -D INPUT -s %IP% -p tcp --syn --dport 22 -j ACCEPT

This example uses a single knock to control access to port 22 (SSH). After receiving a successful knock, the daemon will run the start_command, wait for the time specified in cmd_timeout, then execute the stop_command. This is useful to automatically
In order to make use of the following configuration scheme, it’s important that you have ESTABLISHED,RELATED rules in your iptables firewalling settings. Like this:

iptables -A INPUT -m –state ESTABLISHED,RELATED -j ACCEPT

Otherwise, you may loose your SSH session after those 10 seconds (even if you connected already).
And, of couse, the iptables DROP policy:

iptables -P INPUT DROP

How to knock

Ok, now you have set up your server, how to knock on its ports ?
The easiest way it’s to sue the knock command, that is available in the knockd package as client.
the basic usage of knock is:

knock yourserver port:protocol port:protocol  port:protocol

If you omit :protocol the default it’s to use all TCP, this can be changed using the options -u (all UDP)
Examples:
Knock on 3 TCP ports:

knock 127.0.0.1 7000 8000 9000

You can use this syntax for specifying TCP and UDP packets:

knock 127.0.0.1 123:tcp 456:udp 789:tcp

Client for Window and Mac are available at the url: http://www.zeroflux.org/projects/knock
References:
http://www.zeroflux.org/projects/knock

http://www.portknocking.org/