ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

How to Go Around ISPs Blocking VoIP Ports

Updated on April 12, 2011

ISPs and VoIP Blocking

It's easy to see why VoIP is a technology fraught with danger for many authorities. Whether they're the government or the private sector, it seems that everyone feels that it's simply too dangerous to allow anyone to talk to anyone else for free without restrictions. Corporations can block VoIP either at the behest of governments or to protect their business strategy which includes making users subscribe to their expensive telephone plans. Even hotels which offer Internet services for which the customers pay for can attempt to block VoIP ports so that their own phone services will be used.

Governments of course have a variety of reasons for blocking VoIP. They like to be able to track things and encrypted VoIP is impossible to do so. So the simple solution is to block VoIP in many countries around the world. In this article, we look at the most important way in which this is accomplished and in what situations it is applied. We'll also see some of the ways we can bypass such blocks and the risks that they present.

Blocking VoIP
Blocking VoIP

Bypassing port blocking

In many countries, the companies which provide Internet access are also the ones who provide telephone services. This is because the Internet started off with dial up and they already had the infrastructure in place. Mobile carriers who provide data plans therefore have the ability to restrict VoIP calls on all mobile devices. Hosted mobile VoIP systems suffer greatly though this kind of blocking.

The most common way of blocking VoIP services is by blocking the ports through which they operate. Each VoIP protocol specifies a certain port through which the service is provided. In the case of SIP, this is usually port 5060 or 5061. Since more and more VoIP providers are using SIP as their protocol, it's becoming easy to block this single port and thereby disable most VoIP functionality.

To bypass VoIP blocking, it's necessary to use another port. One way is to ask your VoIP provider whether or not they allow their hosted SIP proxy servers to be accessed through any other port. They might or they might not. If they don't, there's no way to access an SIP service directly.

The other option is to find a "proxy for the proxy" which you can connect to from another port. Though this bypasses the port blocking, it's dangerous since you have to absolutely trust the server through which you're connecting to the original SIP proxy.

These are two of the most important ways by which we can bypass VoIP port blocking by ISPs.


    0 of 8192 characters used
    Post Comment

    No comments yet.


    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at:

    Show Details
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the or domains, for performance and efficiency reasons. (Privacy Policy)
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)