Tag: ip

The TCP #major #classes #of #an #ip #network


Please Whitelist This Site?

I know everyone hates ads. But please understand that I am providing premium content for free that takes hundreds of hours of time to research and write. I don’t want to go to a pay-only model like some sites, but when more and more people block ads, I end up working for free. And I have a family to support, just like you. )

If you like The TCP/IP Guide, please consider the download version. It’s priced very economically and you can read all of it in a convenient format without ads.

Thanks for your understanding!

Sincerely, Charles Kozierok
Author and Publisher, The TCP/IP Guide

IP “Classful” Addressing Overview and Address Classes
(Page 1 of 2)

When the first precursor of the Internet was developed, some of the requirements of the internetwork, both present and future, were quickly realized. The Internet would start small but eventually grow. It would be shared by many organizations. Since it is necessary for all IP addresses on the internetwork to be unique, a system had to be created for dividing up the available addresses and share them amongst those organizations. A central authority had to be established for this purpose, and a scheme developed for it to effectively allocate addresses.

The developers of IP recognized that organizations come in different sizes and would therefore need varying numbers of IP addresses on the Internet. They devised a system whereby the IP address space would be divided into classes. each of which contained a portion of the total addresses and were dedicated to specific uses. Some would be devoted to large networks on the Internet, while others would be for smaller organizations, and still others reserved for special purposes.

Since this was the original system, it had no name; it was just the IP addressing system. Today, in reference to its use of classes, it is called the classful addressing scheme, to differentiate it from the newer classless scheme. As I said at the end of the introduction to this section. classful isn’t really a word, but it’s what everyone uses.

IP Address Classes

There are five classes in the classful system, which are given letters A through E. Table 43 provides some general information about the classes, their intended uses and other general characteristics about them:

Table 43: IP Address Classes and Class Characteristics and Uses

IP Address Class

Reserved for experimental use .

Looking at this table (and at Figure 60 ) you can see that the first three, classes A, B and C, comprise most of the total address space (7/8ths of it). These are the classes used for unicast IP addressing, which means for messages sent to a single network interface. (The blocks also include associated broadcast addresses for these networks.) This is what we usually consider normal IP addressing. You can think of classes A, B and C as the papa bear , mama bear and baby bear of traditional IP addressing. They allow the Internet to provide addressing for a small number of very large networks, a moderate number of medium-sized organizations, and a large number of smaller companies. This approximately reflects the distribution of organization sizes, approximately, in the real world, though the large gulf in the maximum number of hosts allowed for each address class leads to inflexibility and problems.

As you can see, the classes differ in the place where the dividing line is drawn between the network ID and the host ID portions of the addresses they contain. However, in each case the division is made on octet boundaries: in classful addressing, the division does not occur within an octet.

Figure 60: Division of IPv4 Address Space Into Classes

(I don t really need to explain this one, do I? J )

Classes D and E are special to the point where many people don’t even realize they exist. Class D is used for IP multicasting. while class E was reserved for experimental use . I discuss IP multicast addressing later in this section.

Tags : , , , , ,

Business Phone Systems in Phoenix, AZ #phone #systems, #telephone #systems, #small #business #phone #system,


Business Telephone Systems

Whether your business needs dictate a full IP PBX system, a more traditional digital office phone system, or you need to combine the two, you can take advantage of a flexible, feature-rich platform tailored to your needs that will grow with you. Our business phone system experts are available to provide you with a free needs analysis and make specific recommendations to improve your business communications.

Media Management

Know more. Reduce Risks. Manage better. Media Management is an all-in-one telephone system add-on that lets you access recordings of selected office phone calls and other call information, view security footage, and obtain reports of building access records.

Computer/Telephone Integration

With ESI’s VIP™ software, you’ll enjoy a high level of integration between your office phone system and your PC. Database dialing, screen “pops”, call control, voice mail retrieval, and much more are at your command.

All business phone systems and other products offered by Telco Ltd. are designed to give you maximum productivity while being among the easiest to use on the market. Our experts can help you choose the best telephone system configuration for your needs. Serving the Phoenix, AZ metro area.

BUSINESS Telephone Systems

Maximize your productivity without sacrificing on ease-of-use. Choose the digital or VOIP office telephone system that’s right for your business and that will grow with you.

Unified Messaging

Receive email, voice mail, and fax transmissions in one mailbox. Take your communications with you wherever you go.

Business VOIP Solutions

Learn about the multitude of ways you can leverage VOIP (Voice Over IP) in your business to make you more productive and reduce expenses.

Bluetooth integration

Use your favorite Bluetooth headset with your office phone. Manage your cell calls and your business calls all from your desktop phone.

Tags : , , , , , , , , , ,

How to Setup Remote Access For a Computer #how #to #remote #access #a #computer


Managed DNS Services

Remote access is a cool tool to setup if you would like to access your computer remotely from work or while away on vacation.

It gives you full access to your computer, without physically having to be in front of it. Remote access is also a cool way to monitor an IP camera while you are away from your business or home. Although remote access is simple to setup and configure, it can prove difficult to consistently connect to your network if you have a dynamic IP address. A dynamic IP address at your home means that your IP address is constantly changing and it is not fixed. Think of your IP address as your mailing address at your house. If your mailing address was constantly changing, how would you get all those exciting bills and junk mail? You wouldn t. So, dynamic DNS points your dynamic IP address to an easy to remember name.

In order to access your computer or device remotely, you will need to point your device(s) to a static IP address. Static IP addresses are often very expensive, and many Internet Service Providers (ISPs) don t even offer them to residential customers. The easy and (free) answer is to setup dynamic DNS.

Dynamic DNS takes your dynamic IP address and points it to an easy to remember name. So, your IP address would point to, yourname.no-ip.org.

Okay, cool, but this doesn t solve the issue of my dynamic IP address. What happens when it changes?
What happens when my IP address changes and my easy to remember name no longer works? Many wireless routers have integrated dynamic DNS capabilities, meaning when you configure it with your No-IP account, your hostname will automatically update when your dynamic IP address changes. This means that your computer, device or network will always be accessible remotely.

But what if my router doesn t have No-IP as an integrated dynamic DNS provider?
No worries. We offer free software that you can install on your computer, the No-IP Dynamic Update Client. Our Dynamic Update Client is available for Windows, Mac and Linux. This software takes up less than 8mb of space on your computer, but performs the same way as an integrated DDNS solution in your router would. As long as the Dynamic Update Client is running and is configured properly, it will update your easy to remember name (hostname) with your current IP address.

So how do you gain remote access to a computer with dynamic IP address? First, start by creating a No-IP free dynamic DNS account. You can check out this video if you need help. Then, check out these helpful support guides:

Free Dynamic DNS. Getting Started Guide
Using Remote Desktop with No-IP
How to Setup a Webcam and Access it From Anywhere
Remote Access Support Articles
Setting up a FTP Server on Your Computer

Have questions or need help? Don t hesitate to open a support ticket and our friendly Technical Support Staff will help!

Tags : , , , , , , , ,

Voice over IP Security #voice #over #ip #services


Voice over IP Security

Voice over IP Security

Security best practices derived from deep analysis of the latest VoIP network threats

VoIP security issues are becoming increasingly serious because voice networks and services cannot be protected from recent intelligent attacks and fraud by traditional systems such as firewalls and NAT alone. After analyzing threats and recent patterns of attacks and fraud, consideration needs to be given to the redesign of secure VoIP architectures with advanced protocols and intelligent products, such as Session Border Controller (SBC). Another type of security issue is how to implement lawful interception within complicated service architectures according to government requirements.

Voice over IP Security focuses on the analysis of current and future threats, the evaluation of security products, the methodologies of protection, and best practices for architecture design and service deployment. This book not only covers technology concepts and issues, but also provides detailed design solutions featuring current products and protocols so that you can deploy a secure VoIP service in the real world with confidence.

Voice over IP Security gives you everything you need to understand the latest security threats and design solutions to protect your VoIP network from fraud and security incidents.

Patrick Park has been working on product design, network architecture design, testing, and consulting for more than 10 years. Currently Patrick works for Cisco as a VoIP test engineer focusing on security and interoperability testing of rich media collaboration gateways. Before Patrick joined Cisco, he worked for Covad Communications as a VoIP security engineer focusing on the design and deployment of secure network architectures and lawful interception (CALEA). Patrick graduated from the Pusan National University in South Korea, where he majored in computer engineering.

Understand the current and emerging threats to VoIP networks

Learn about the security profiles of VoIP protocols, including SIP, H.323, and MGCP

Evaluate well-known cryptographic algorithms such as DES, 3DES, AES, RAS, digital signature (DSA), and hash function (MD5, SHA, HMAC)

Analyze and simulate threats with negative testing tools

Secure VoIP services with SIP and other supplementary protocols

Eliminate security issues on the VoIP network border by deploying an SBC

Configure enterprise devices, including firewalls, Cisco Unified Communications Manager, Cisco Unified Communications Manager Express, IP phones, and multilayer switches to secure VoIP network traffic

Implement lawful interception into VoIP service environments

This IP communications book is part of the Cisco Press Networking Technology Series. IP communications titles from Cisco Press help networking professionals understand voice and IP telephony technologies, plan and design converged

networks, and implement network

solutions for increased productivity.

Category: Networking IP Communication

Covers: VoIP Security

Online Sample Chapter

Tags : , , ,

Online Camera – Live Cams Viewer: Webcam Video Streaming, Security IP Camera Viewer, Worldview


Online Camera – Live Cams Viewer: Webcam Video Streaming, Security IP Camera Viewer, Worldview Weather Monitoring, City Traffic Cam, CCTV Surveillance Web Cameras for iPhone

Publisher’s Description

From ODESSA GLOBAL: Over 200,000 users, over 11,000 cameras worldwide!View and remotely control thousands of public web cameras from around the world right from your iPhone and iPad. Watch almost every place on Earth (we add cameras by your requests inside the app).Connect and monitor your own private Foscam, Axis, Trendnet, Panasonic, etc. IP cameras for home and office video surveillance. Have a live webcam video from everywhere, always!Online Camera – Live Cams Viewer features: Search cams by keywords and browse by world map Select cams by Country, HD, Category like cities, weather, traffic, restaurants, offices, zoos, airports, beaches, etc. Like and vote for the best cameras, customize your cam collection Pan, tilt, and zoom live video with motion controls from your iPhone and iPad Save camera shots, get camera information Rewind recorded camera shots for the past 24 hours if you missed to view liveLeave a review at the App Store with your wishes and requests!

What’s new in this version:

UI improvementsPerformance improvements


Add Your Review

You are logged in as . Please submit your review for Online Camera – Live Cams Viewer: Webcam Video Streaming, Security IP Camera Viewer, Worldview Weather Monitoring, City Traffic Cam, CCTV Surveillance Web Cameras

Thank You for Submitting Your Review, !

Note that your submission may not appear immediately on our site.

Update Your Review

Since you’ve already submitted a review for this product, this submission will be added as an update to your original review.

Thank You for Submitting an Update to Your Review, !

Note that your submission may not appear immediately on our site.

Tags : , , , , , , , , , , , , , , , , , , , , , , ,

ESI Estech Systems #esi, #estech #systems, #estech #systems #inc., #cloud, #cloud #business #phones, #cloud


Estech Systems, lnc. (ESl) Highlights:

  • Celebrating 30 years in business
  • Provider of end-to-end business solutions
  • Full solutions portfolio (Cloud, Hybrid, Pure IP SIP dial tone)
  • 1,500+ Certified Partners nationwide
  • 400,000+ solutions sold
  • Billions of minutes called in the Cloud
  • Thousands of National Accounts
  • American-engineered technology
  • U.S.-based, best-in-class Technical Support
  • Network Operations Center (NOC) located in Plano,TX

The most integrated Cloud PBX in the market

Cloud Services

Simple and intuitive cloud communications, plus all the robust features you need to boost efficiency and control costs.
Learn More.

Hybrid Cloud Services

Not ready for the cloud just yet? Get the reliability of an on-premises solution with the flexibility of VoIP.
Learn More.

On-Premises Products

Sophisticated, yet simple with unique call-handling features that are easy to use and manage.
Learn more.

What We Believe

Business doesn’t get done without communication.
That’s why we believe that business communications shouldn’t only be powerful. They must also be easy and intuitive to use.

We believe that you should have it all. Not only should your communications solution offer simplicity. Choosing an ESI solution gives you a competitive edge – whether you select a cloud, on-premises solution or a mix. You can’t go wrong with ESI.

“Technology is everywhere, yet most users don’t leverage the full power of these solutions to drive business. Features and functions meant for productivity are simply too complicated and therefore go unused.

At ESI, our focus is on making intelligent technology that is intuitive and easy to use, empowering employee productivity to fuel customer satisfaction.”
-George Platt, ESI CEO



ESI Introduces the First “Smartphone” for the Desktop with the ePhone7

ESI Reveals Enhanced Ditto Mobile Application to Support the Mobile Workforce

ESI Outlines Best Practices for Balancing Employee and Company Expectations with BYOD

ESI Outlines Five Keys to Successfully Selling and Marketing Cloud Solutions

Featured Customer Story

The Most Powerful Business Phone You Will Ever Use

Tags : , , , , , , , , , , , , , , , , , , , , , , , , , , , ,

Detect – DCWG #roadrunner #dns #server #ip



Table of Contents

How can you detect if your computer has been violated and infected with DNS Changer?

An industry wide team has developed easy “are you infected” web sites. They are a quick way to determine if you are infected with DNS Changer. Each site is designed for any normal computer user to browse to a link, follow the instructions, and see if they might be infected. Each site has instructions in their local languages on the next steps to clean up possible infections.

For example, the http://www.dns-ok.us/ will state if you are or are not infected (see below).

  • No Software is Downloaded! The tools do not need to to load any software on your computer to perform the check.
  • No changes are performed on your computer! Nothing is changed on your computer when you use sites like http://www.dns-ok.us/ .
  • No scanning ! The are you infected with DNS Changer tool does not need to scan your computer.

If you think your computer is infected with DNS Changer or any other malware, please refer to the security guides from your operating system or the self -help references from our fix page (http://www.dcwg.org/fix ).

The following table is a list of all easy are you infected sites. It includes the links to the security organizations who are maintaining the sites. Each site has instructions in their local languages on the next steps to clean up possible infections.

If you are not affected by DNS Changer then do nothing.

If the Check-Up Site indicates that you are affected then either follow the instructions on that site or go to the FIX page.

Manually Checking if your DNS server have been Changed

The following pages would help check to manually see if you have DNS Changer DNS servers configured on your computer. Use of the check up pages are more effective, but some would want to check manually.

  • Checking for DNS Changer on Windows XP
  • Checking for DNS Changer on Windows Vista (pending)
  • Checking Windows 7 for Infections
  • Checking OSX for Infections

Would my Service Provider Help Me?

Many service providers are notifying their customers. They are creating help pages that will help you detect and clean up DNS Changer from your system. Here is a partial list. Please contact your SP if you do not see them on the list.

Tags : , , ,

Phone Systems #ip #phone #systems


Video Conferencing

Don t know where to get started with phone systems.
We re fast, free and here to help.

Searching through hundreds of different phone systems and providers can be time consuming and difficult. We re a completely free service that connects you with the best Australian phone systems provider. No matter what your budget, size, or requirements we can help by putting you in touch with local specialists who understand what you need and want. We also provide technology solutions for businesses including security systems, headsets and much more.

Common questions:

What phone system do I need?

There are many different phone system options including purchase or monthly rental plans and new or refurbished systems. New phone systems are usually equipped with more features and are more equipped for VoIP integration which be more costly. Rental or second hand phone systems are a great way to reduce outlay. Most phone system providers will provide you with customised handset, line and extension options for small, medium and large business phone systems based on your requests.

Do I buy or rent?

A popular option for small and medium businesses is to rent their phone system as an all-in-one solution. This allows smaller businesses to get access to great features they desire, which may only available on newer phone systems. Many large businesses and corporations choose to buy their phone system outright, but rent options are available for businesses of any size. Renting can also be a great option if you want to upgrade or move in the near future as you eliminate the capital outlay of a more permanent solution, as many rental packages include optional extras like cabling in their monthly price.

Should I buy a new phone system?

New phone systems can give your business access to amazing new technologies such as video conferencing and can integrate well with your unified communications solution. If you are unsure about what features you need, be sure to let the provider know so they can discuss what options would best suit your business.

What is VoIP? Do I need it?

VoIP stands for Voice over IP. Instead of your phone calls being made over the traditional copper system, calls are made over your broadband connection.

Many people believe that VoIP phone systems cas help their business save money. However, without having a provider check your current phone bills, there may not be enough savings to justify the cost of the equipment. Depending on your requirements, a hybrid phone system may be the answer. (A mix traditional telephony and VoIP.)

How much do phone systems cost?

The cost of your phone system is based on:

  • What type of system you are getting (New, refurbished or VoIP)
  • If you are renting or buying outright
  • Which brand is the most suitable
  • What handsets and models meet your needs

We’re here to connect you with the best phone system providers. To find out how much a phone system would cost your business, get an obligation free quote by choosing the best option that suits your business below.

What features should I get?

Each business has unique needs and should consider what features would help improve the productivity and professionalism of their business. Some of the most popular features for phone systems are:

Can my phone system grow with my business?

Absolutely! Many phone systems are now designed for up to 24 users, and some can accommodate hundreds and thousands of users. Something to let your phone system provider know is if you have multiple offices or remote workers you would like to connect to your phone system.

What phone systems work with the NBN?

A common misconception is that all traditional telephony systems such as ISDN and PSTN systems will not work on the NBN and that only SIP/VoIP phone systems will work. Most traditional phone systems will still work when the NBN rolls out. However, it can be a great time to upgrade your existing phone system to take advantage of some of the fantastic new technologies available.

Why choose us?

  • Completely free service
  • We don’t mark up prices
  • Knowledgeable staff
  • Obligation-free advice
  • 100% customised quotes
  • All-in-one tech solutions
  • We can help with more than just phone systems

Get started now

We’re the experts in phone systems. and more!

We’ve noticed how overwhelming it is for consumers to make informed decisions about phone systems and other communications and technologies for their business. The rate of technology development and the number of phone systems providers makes it almost impossible for most businesses to keep up to date on what’s out there. We’re a team dedicated to helping provide great phone systems and other business technology solutions across Australia – completely free of charge. Our exceptionally experienced staff are always ready to assist you in finding a the perfect communications solution for your business at the best available price.

I’m ready to get started!

Select the best statement for your business:

Tags : , ,

Reverse DNS check #email #blacklist #check, #blacklist #monitor, #spam #blacklist #check, #dnsbl #check, #rbl


Reverse DNS test

Computer networks use the DNS to determine the IP address associated with a domain name. This process is also known as forward DNS resolution. Reverse DNS lookup is the inverse process of this, the resolution of an IP address to its designated domain name.

While receiving an email message, a mail server may try to attempt reverse DNS lookup. If the lookup fails (no PTR record) or PTR record is not forward confirmed or looks like generic, the message may be marked as spam or rejected.

AOL reverse DNS requirements

To reduce spam rate AOL rejects email originated from servers that do not comply to requirements described here . To ensure your email delivery to AOL and many other recipients our proactive blacklist monitoring service performs FCrDNS test and dynamic IP address test .

Check reverse DNS

FCrDNS test

FCrDNS, or Forward Confirmed reverse DNS, is when an IP address has forward and reverse DNS entries that match each other. For FCrDNS verification, first a reverse DNS lookup is done to get a list of PTR. Then for each domain name mentioned in the PTR records, a regular DNS lookup is done to see if any of the A records match the original IP address. If there is a forward DNS lookup that confirms one of the names given by the reverse DNS lookup, then the FCrDNS check passes.

IP address resolves to mail.domain.com.
Host name mail.domain.com resolves to IP addresses and
Thus, reverse DNS for IP address is forward confirmed.

Dynamic IP test

Many mail servers, including AOL, check domain names retrieved using reverse DNS lookup to see if they are likely from dialup users or dynamically assigned addresses. Owners of such IP addresses typically assign them generic names such as “1-2-3-4-dynamic-ip.example.com” or “11-22-33-44-host.hostingcompany.com”. Since the vast majority, but by no means all, of email that originates from such addresses is spam, many spam filters refuse email originated from such sources. Here is an example of typical bounce message

#5.5.0 smtp;550 We do not accept mail from dynamic IPs.

Debouncer tests if your reverse DNS record match widely used naming patterns used to detect dynamic IP addresses or generic PTR records.

Test if your IP address is blacklisted

Tags : , , , , , , , , , , , ,

IP Pbx office phone system Dubai #pabx #dubai,pabxdubai,pabx #installation #dubai,ip #pabx #dubai,telephone #system #dubai,office


Follow us!

For Enquiries call: +971 4 4504145

Models Models

PABX DUBAI provides telephony solutions Installation for companies,businesses,professional offices,hotels and public administrations with guaranteed value for money .PABX DUBAI offer wide variety of telephone systems Pbx / Pabx Solutions,and supply of telephony products all across the region. We cater for businesses of any size, and offer a diverse product range from basic two- user phone systems through to multi- user systems with 1000 users. we provide telephone systems,IP Phone systems, Digital Phone systems or Wireless phone systems, whether you are 2, 25 or up to 1000 employees. Just getting started or already established we have a phone system solution for your company. Small office ip phone system technology delivers so much more today than just a dial tone.

Today, a small office phone system is increasingly part of a converged network—an Internet Protocol (IP) network that seamlessly ties together voice, data, video conferencing, wireless, instant messaging, and other business- critical communications tools and applications.We can help you get the best out of your telephone system.

PABX / PBX Telephone Systems

Models Models Models Models

IP PABX stands for Internet Protocol Private Automatic Branch Exchange. In simple terms, it is an Office’s own full- IP telecom system.Buy your PBX choosing from the wide range of analog, digital, ISDN and VoIP systems available with us. We are a company specializing in VoIP and fixed telephony for businesses, offices, shops and accommodation in Dubai, UAE and offers a professional and timely service online and onsite. With a voice/data solution for every business need, from small offices to branch locations to the largest multi- site business, we do have the telephone systems and Gateways give you the flexible, scalable foundation you can use to economically and reliably deliver the rich telephony applications of ip telephony over your data network. Whether you are interested in upgrading your current telephone system or need advice on installation of digital or analogue lines, we are here to help.We understand the everyday problems that businesses face today, and as such we work closely with all our clients to implement fully integrated communications solutions.
We also implement additional features like voice- mail, computer telephony integration, call management software, call logging and call recording systems. Because of our wide range of experience and our commitment to service, we are the choice telephone systems provider for many small to medium sized business.
We have systems and PBXs of the following brands and models:

Tags : , , , , , , , , ,