ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

Integrating VoIP and Fax

Updated on March 24, 2011

Fax and the Internet

With all the attention being paid to VoIP and talking over the Internet, many forget about an important service which has also traditionally relied on phone lines, namely fax. Though the importance of fax has gone down recently due to the proliferation of scanners and email, there are still millions of fax users worldwide and very often the only way a person can receive a copy of a document is via fax and a telephone connection. So those ditching the PSTN system in favor of VoIP need to understand how fax works with it.

Unfortunately, fax doesn't work very well with a default VoIP set up. There's nothing preventing someone from hooking up a fax machine to the VoIP system since it behaves just like a regular phone system. But the results won't be pretty. The primary reason for this is that VoIP digitizes and encodes the analog signals of a regular phone line using whichever codec is most appropriate and these manipulations are targeted towards voice data alone. When we try and do the same thing to fax data, it doesn't work out so well. Because of this, we need to tweak the VoIP set up in order to make it work with fax systems.

Fax and VoIP
Fax and VoIP

Making Fax work with VoIP

In order to ensure that faxes aren't broken up by VoIP systems, the international body that's responsible for these things has created the T.38 standard. This is a special protocol which specifies all the "fax specific" things which need to be done to make sure that outgoing and incoming faxes are not garbled.

This protocol is implemented in the ATA routers to which you connect your regular telephone lines and are responsible for the conversion of digital into analog and vice versa. Of course, you'll also need a VoIP gateway which supports the same protocol to complete the set up. Conversely, you can do away with a fax machine entirely and set up your server with fax software which makes it behave just like a fax machine to send and receive images.

Finally, we have separate fax machines which are specifically designed to work with "Fax Over IP" or FoIP as it is called. Using these specialized machines, fax over the Internet is a snap. Just hook it up like a regular telephone system and you should be ready to go. One of the measures taken to maintain the integrity of FoIP is that each packet contains some data from the previous packet. This means that more than one packet has to be lost in order to lose the entirety of the contents. It's just one of the ways the T.38 protocol uses to ensure that the fax arrives in decent shape at the other end.

Call your business VoIP proxy service and ask them how they handle faxes. Hosted SIP VoIP systems will surely have robust mechanisms in place to accommodate their customers.


    0 of 8192 characters used
    Post Comment

    • davenporte profile image


      7 years ago

      this is pretty cool, fax over ip, not so long ago many thought that voice over ip was strange,this info is great thanks


    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)