In previous Expert Witness articles I have written about ‘next generation’ broadband, both from BT with their forthcoming 21CN services and also the local loop un-bundlers like Tiscali et al. These next generation services are based on the ADSL 2+ standard and support speeds of up to 24Mbit/s. However, there are two potential problems for your end users that need this amount of bandwidth; the rollout and reach of next generation broadband. In this month’s Expert Witness, I look at the facts and myths surrounding the use of ‘bonded broadband’ to address these issues. Bonding multiple ADSL lines together can be a cost effective way of providing more bandwidth to those customers that need it. For example, you could install 4 x 2Mbit/s ADSL lines where a customer needs 8Mbit/s of bandwidth, but can’t get an 8Mbit/s line.
1. 24Mbit/s ADSL2+ services are available everywhere from LLU operators now and from BT next year.
MYTH - It is true that LLU operators have been selling 24Mbit/s services for some time and BT are launching theirs in April 2008. However, the LLU operators provide services in less than 20% of telephone exchanges and BT’s 21CN rollout means that it will be 2011 before every exchange has been upgraded to support 24Mbit/s. In the mean time, bonding may be a suitable alternative.
2. Even with ADSL2+ services my customers rarely get 24Mbit/s.
FACT - Like all ADSL services, the actual bandwidth available is based on the quality and length of the customer’s telephone line. Many resellers will be familiar with this characteristic of ADSL from selling ‘IPStream Max’ services. Although Max supports up to 8Mbit/s, in reality this is only achievable if the customer is located very close to their local telephone exchange. With Max, across an entire customer base, you may expect an average throughput of 5.5Mbit/s, with some people achieving the full 8Mbit/s and the worst achieving less than 2Mbit/s. In those situations where the customer needs more bandwidth than a single line then bonding may be able to help.
3. Bonding multiple lines together will increase the amount of bandwidth available to any application.
MYTH - It is very important to understand the customer’s reasons for needing more bandwidth before proposing bonding multiple lines together as a solution. There is more than one type of bonding solution on the market. Some require support from the service provider and some don’t. There are a number of questions that need to be answered before making a recommendation to your customer. Firstly, do they need to increase the upstream bandwidth, the downstream bandwidth or both? Secondly, are they trying to increase the bandwidth for multiple streams of data or just one stream of data? If you need to do just the upstream, then you could use the load balancing or load sharing feature of most DSL routers that support multiple lines, but if you need to do both upstream and downstream then you will need a service provider that supports the multilink PPP standard or perhaps some proprietary system.
4. Multilink PPP will only work if the ISP specifically supports it.
FACT – Although multilink PPP is normally the best choice for applications that require upstream support, downstream support, support for single stream and multi-stream. Multilink PPP is a low level protocol that is setup between the CPE and the equipment that terminates your service at the ISP. If the ISP does not specifically support multilink PPP then it will not work, regardless of the CPE equipment that you are using.
and finally...
The cost of bonding ADSL lines together can be very much cheaper than an equivalent leased line, even when specialist equipment is taken into account. Consequently there are a number of Griffin partners doing very well targeting the leased line replacement market with a bonded solution. The key is to work out what most of your customers are trying to achieve, how big you think the overall opportunity is and then get good advice on how to bring a suitable product to market. Remember also that leased lines usually come with much better SLAs than ADSL so make sure you set the expectations of your customers accordingly.
If you would like to discuss this or any other subject please email marketing@griffin.com
Source: Comms Business Magazine January.
Adrian Sunderland
