BT, BSkyB, O2 and TalkTalk are among ten ISPs to commit to the Open Internet Code of Practice. (9-page / 52KB PDF) However, Virgin Media, Vodafone and Everything Everywhere have so far elected not to sign up to the code, with Virgin citing concerns with its wording.
Under the code the signatory ISPs are allowed to offer "products" that may restrict "full internet access", but they have committed not to use the term 'internet access' to "describe or mark such products and ensure that any restrictions are effectively communicated to consumers".
In addition, the code allows for the ISPs to restrict open use of the internet through "traffic management" of their services. ISPs sometimes block or slow down users' access to some content during busy periods on their networks. This managing of congestion, together with blocking of services when ordered to do so by courts or law, as well as the blocking of sites and services that promote child pornography, count as legitimate restrictions to ISPs' deliverance of a full internet service.
Deploying age controls or complying with data caps or download limits as specified in consumer contracts are among the other permissible reasons ISPs can restrict their service.
The code requires that ISPs do not use traffic management "in a manner that targets and degrades the content or application(s) of specific providers" and ensure that a 'best efforts' internet access is a "viable choice" to consumers even where other "managed services" are available.
The ISPs signed up to the code have also agreed to operate "clear and transparent traffic management policies".
A new complaints system has also been established under the code to allow "providers of internet-based content, applications and services" to raise "evidenced concerns about possible instances of negative discrimination" with the individual ISPs. Should complaints be unresolved the Broadband Stakeholder Group (BSG), which is an independent advisory body that helped facilitate the agreement of the new code, will report the incidents to the Government and Ofcom, the telecoms regulator. Ofcom would then have to decide whether to investigate further.
In November last year Ofcom outlined its approach to the 'open internet' issue. It accepted that some traffic management techniques are necessarily used by ISPs to ensure an efficient service but said that ISPs must leave enough spare network capacity to deliver a 'best efforts' service, where access is generally "open" and "equal" for users.
At the time Ofcom said that it was happy to rely on the market to ensure that traffic management is legitimate and not discriminatory but that that strategy was dependent on ISPs being transparent with consumers "as to the nature of the services they offer". It said that ISPs were not, at that stage, providing users with enough information about their service and the traffic management they carry out.
Culture Minister Ed Vaizey welcomed the new establishment of the new code.
"This voluntary agreement is great news for consumers," he said. "It marks a significant commitment from the leading ISPs to uphold the principles of an open internet and gives certainty to their customers. The internet has been built on openness and low barriers to entry, and this agreement will ensure that continues. By committing to transparency, these ISPs are empowering their customers to make informed decisions about the services they want."
Pamela Learmonth, chief executive of BSG, added: "With this code ISPs are making practical, tangible commitments to the open internet. The open internet model has long supported the innovation of new services and allowed consumers to discover informative, useful and creative applications, services and content and this must continue. At the same time the code will also support an environment where new business models for internet-based services to the benefit of consumer choice can be developed."
The BBC and Microsoft-owned Skype also welcomed the code and said it would help to ensure consumers can choose which content to access.
However, Virgin said the wording of the code was "open to misinterpretation and potential exploitation" and that it would seek "greater clarity" before it would consider signing-up to the framework, according to a report.
Vodafone said that restrictions on the use of the 'internet access' term had put it off signing the code. Everything Everywhere, operator of the T-Mobile and Orange mobile networks, said it would "continually review" whether to sign-up but said it was "too early to know how a code of this type will affect customers' internet experience" to do so currently, according to the report.
Separately the European Commission has launched a consultation on 'net neutrality' issues and has said the responses will help it draft formal recommendations regarding the "preservation of the open internet".
Through its consultation the Commission is seeking views on "internet traffic management, including congestion management, managed services and privacy issues; transparency, in particular regarding the actual internet performance (speed and quality) and restrictions of internet access products; the possibility for consumers to switch operators and internet interconnection issues between network operators," according to a statement it issued.
The consultation is open until 15 October 2012.
"Today there is a lack of effective consumer choice when it comes to internet offers," Neelie Kroes, EU Commissioner responsible for the Digital Agenda, said. "I will use this consultation to help prepare recommendations that will generate more real choices and end the net neutrality waiting game in Europe."
Net neutrality is the principle that an ISP will deliver all content requested by a customer equally, not allowing content producers which pay it to have preferential access to its subscribers.
Controversy over net neutrality has been most prevalent in the US where some telecoms companies have said that content producers should share the cost of network building and maintenance. Opponents of that view claim that subscribers' fees to ISPs should buy them access to all information equally, not to a service in which some content is prioritised because of deals between ISPs and content producers.