The story
BE's service utilised ADSL2+ (ITU G.992.5) and was one of the few UK ISPs to offer the Annex M extension to increase upload speeds anywhere up to the full technical maximum of ~2 Mbit/s for its BE Pro customers. The end user's router communicated with the telephone exchange using Ethernet over ATM (ETHoA, RFC 1483).
One of BE's advertised claims was that it did not carry out traffic shaping in any way and that traffic was only limited by available bandwidth and by any congestion at the local exchange. BE did, however, block SMTP traffic over port 25 to and from external destinations for users with dynamic IP addresses in order to prevent its dynamic IP pool being blacklisted. The result was that a user with a dynamic IP address could only use BE's own SMTP server or one configured to use non-standard ports for sending email. Users who wished to host their own mail server were required to subscribe to a service with a static IP address.
On 15 October 2007 O2, also owned by parent company Telefónica Europe, launched its own broadband product delivered over the BE network infrastructure. In effect, this resulted in two broadband companies delivering services over a platform on which previously only one company was operating. This, coupled with the fact that there were officially over three times the number of subscribers using the platform since the launch of O2Broadband, caused some BE users to voice concerns over the future performance, stability and contention of the service. Such concerns were generally groundless as BE upgraded its network capacity to accommodate new customers.
Wholesale Network Access
In addition to the BE and O2 brands being delivered over the same network, since 10 March 2008, BE/O2 resold wholesale access Archived 2 February 2011 at the Wayback Machine to its network to other providers. The first of these companies was Vaioni, which launched an "up to 20 Mbit/s business class ADSL2+ service" featuring up to 2.5 Mbit/s upstream and a guaranteed 10:1 contention ratio with prices starting from £140.99 per month. Vaioni's product, branded 'Ultra 20', was aimed at small to medium-sized businesses and schools.
In August 2009 the UK ISP Andrews & Arnold entered into an agreement to use BE's core and LLU networks to augment BT's legacy 20CN and 21CN infrastructure. By the time that BE was sold to BSkyB in 2013 many other business connectivity providers offered BE wholesale services.
Network Upgrades
On 6 October 2011, BE announced an overhaul of its core network to increase bandwidth, prepare for a transition to IPv6 and improve network resiliency. During this time customers with static and dynamic IP addresses were assigned new addresses; BE took the approach of rebuilding its entire network, migrating customers, changing IP address blocks and incurring a small one-off period of downtime during an end user's migration. This migration was implemented in phases with a transitional period with both old and new network settings operating concurrently.
BE also changed its methods of assigning static IP addresses, selling netblocks of one, six and fourteen as opposed to the old system of a group of addresses from a pool of arbitrarily available IPs. Customers were planned to be migrated over a six to eight months period.
From Wikipedia’s article on Be Un Limited, shared under CC BY-SA 4.0.4