As part of a set of changes to Quality of Service controls on the BT Wholesale IPstream Max and Max Premium products, extra BRAS Data Rate (IP Profile) settings are to be introduced.
The Max product which is used for millions of UK ADSL connections is to have some tweaks that may improve the experience for people who connect in the speed range of 250Kbps to 2Mbps. There is a setting applied to each line, in addition to the basic sync speed the ADSL modem connects at, called the IP Profile (sometimes referred to as the BRAS Data Rate) which controls the speed a which data can be downloaded. It is used both in the dimensioning of the backhaul from the exchange as well as the Quality of Service (QoS) settings which allow an ISP to book an assured rate for a specific period on a line.
Currently there are sixteen IP Profile values possible, with an additional four at 350Kbps, 750Kbps, 1250Kbps and 1750Kbps to be added on 31st July 2007 (the current settings are documented in one of our FAQ's). This should mean that someone now syncing at just under 1152Kbps, e.g 1056Kbps would get an IP Profile of 750Kbps, rather than the 500Kbps they currently get. No changes have been announced to the way the IP Profile waits for three days before increasing to match the setting for your current sync speed.
Any speed boost is a welcome one, and while the changes will not break speed records for those on long lines, any extra speed is welcome. With ADSL2+ pencilled in by BT Wholesale for 2008, we suspect that these tweaks to the IP Profile may be the largest speed boost those living a fair distance from their exchange will see for some time. This is because ADSL2+ will only give marginal improvements on lines over around 4.5km in length, unless options like Seamless Rate Adaption (SRA) and bonding are employed.
The main reason for the changes appears to be that services that make use of the QoS capabilities were wasting more of the ADSL speed than need be. QoS sessions are something broadband consumers do not see much. Generally it is only used by products such as BT Vision, where a stable download speed is needed to ensure a video stream is watchable. When an assured rate session is booked, checks are made to ensure capacity is available on the customers line and the exchange and only then is the assured rate provisioned, after which this reserved bandwidth will become immune to exchange based contention.