Some residential Verizon Internet subscribers have recently noticed a curious result when they accidentally mistype a Web site address in their Web browsers: rather than receiving an error message, or being re-directed to a search engine page that has been configured by the browser to handle misspelled URLs, they end up at a Verizon search page. This occurs because Verizon has changed the way it uses the Domain Name System (DNS) to translate misspelled user-typed URLs; the company essentially creates a new default setting that overrides functionality at the network endpoints, and re-directs the user to its own site.

Most users will likely find this to be a fairly minor issue since they will eventually find the site they were looking for regardless of what their browsers return when a DNS look-up fails. But there are some problems with what Verizon is doing: the departure from agreed-upon DNS technical standards may impair the functionality of certain network-based applications, and Verizon is overriding consumer choices without providing meaningful alternatives.

Although the majority of DNS look-ups come through browsers as users surf the Web, other applications that make use of the DNS standard may fail to work properly as a result of Verizon’s choice not to follow the published protocol. The DNS operates under open standards maintained by the Internet Engineering Task Force (IETF), the body responsible for publishing all of the most common Internet protocols, and any application developer can build products that make use of the standards. Consider a spam filter that queries the DNS to find out whether certain domain names are valid. The filter expects to receive an error for invalid domains, and is built to respond accordingly by rejecting email from domains that do not exist. But if the filter were to run on the Verizon network, it may no longer receive the appropriate error, and would therefore respond incorrectly. In short, it wouldn’t realize that the domain is invalid.

This may seem like a minor technical issue, but back in 2003, VeriSign — which administers all domain names ending in “.com” and “.net” — decided to employ a similar technique to what Verizon is doing. In a stern letter demanding that VeriSign cease the practice of re-directing failed DNS lookups to its own portal, ICANN (an organization that oversees the technical operation of the DNS) noted that the effects of the practice “appear to be significant, including effects on web browsing, certain email services and applications, sequenced lookup services and a pervasive problem of incompatibility with other established protocols.” Although VeriSign’s actions likely affected all Internet users, whereas Verizon’s behavior only impacts its own subscribers, there is no question that the failure to follow an established protocol may have negative consequences.

Verizon’s actions also override consumers’ control over their own browsing experiences. Consumers may have a preferred service that handles DNS errors through a browser plug-in or through the browser itself, but with Verizon DNS Assistance these services will no longer work. Although Verizon offers a way for consumers to opt out of DNS Assistance, the mechanisms to do so are much too complicated for average Internet users who may fear that tinkering with their network settings could disrupt their Internet connectivity altogether. The Verizon opt-out language itself warns users that they may encounter connectivity problems if they travel with a computer that has been used to opt out.

One of the questions surrounding this issue is how Verizon’s DNS Assistance relates to the Internet neutrality debate. While Verizon’s actions are certainly discriminatory in the sense that the company chooses to provide its own content when a DNS look-up fails, rather than allowing end users’ applications to respond on their own, this is not the primary form of discrimination that keeps most neutrality advocates awake at night. Verizon’s behavior reminds us, however, of the powerful position that ISPs occupy on the network.

Although the practical effect of Verizon’s move may be small, the overall effect on innovators and application developers could potentially be large if they feel the need to develop two implementations of their products – one that works on the Verizon network, and one that works everywhere else. In light of this, DNS failure decisions may best be left to end user applications.

This entry was posted on Friday, November 30th, 2007 at 2:02 pm and is filed under CDT, Internet Neutrality. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.