A Manchester-based service provider claims to have
achieved a first-year return on investment of 60% for one of its
clients by using traffic load-balancing tools to aggregate multiple
DSL (fast data over phone lines) connections. This has provided
large amounts of bandwidth for a much lower price than equivalent
leased-line services.
Analysts have said that aggregating DSL in this way can bring cost
savings for branch offices and small to medium-sized
enterprises.
Supplier VGL is currently providing aggregated DSL connections to
housing group Opal at three sites, with a further three to go, and
will eventually provide connections for up to 800 users.
Load-balancing equipment from Rainfinity allows VGL to make use of
much cheaper DSL connections where previously leased lines would
have been used. VGL said a 2mbps leased line costs between £10,000
and £15,000 while the equivalent DSL line costs about £1,800.
DSL connections cannot be considered equivalent to leased lines
because real bandwidth is impaired by "contention" from other users
and because of the lower degree of reliability inherent in DSL
technology.
But internet link load-balancing tools allow these issues to be
overcome by providing a greater amount of bandwidth than would have
been necessary with a leased line and then distributing traffic
between connections to achieve a smooth flow.
Neil Rickard, an analyst with Gartner, said, "It is possible to
aggregate connections going outwards using a router, but to do the
same to incoming traffic from the public internet, load-balancing
tools are required. Aggregating many DSL lines will give greater
reliability and will increase bandwidth rapidly without putting the
bill through the roof.
"DSL connections give a large amount of bandwidth for the money but
may very often be over-subscribed and you will end up getting a lot
less bandwidth than you think with contention. Also, service
providers do not give such stringent service guarantees. This can
be mitigated by getting DSL from different suppliers and
load-balancing them."
Rickard added that the solution is best suited to users that need
to move large amounts of data traffic do not require real-time
delivery, as necessitated by video or voice connections.
Cost comparison
- Leased line cost per year for 10mbps line: £50,000
- 20 x 2mbps DSL business standard connection (£30,000) plus
Rainconnect licence (£4,000) total: £34,000.