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Bandwidth diversification

Bandwidth diversification When building a bandwidth management strategy, a careful selection of ISP technologies can provide significant benefits.

Below is a sample list of link technologies with notes on how to maximize them.

Link type	Comments
T1/E1 circuits and other symmetrical circuits	These links are widely used in organizations, and they offer symmetrical bandwidth (T1s are 1.544Mbps and E1s are 2.048Mbps). They come with SLAs which ensure maximum uptime.Recommended uses are for business-critical applications such as VPN services, SMTP services, hosted applications or services and VoIP.Other symmetrical circuits are available to meet higher throughput requirements, such as DS3 and fiber circuits. These can reach speeds of over 1Gbps depending on locations and ISPs.
DSL	All flavors of DSL share a common factor: they are low-cost compared to many ISP links and widely available. The most common flavor is ADSL, which enables greater download speeds than upload speeds. A common use for these links in organizations is for download-centric activities such as web surfing and peer to peer activities. By combining multiple DSL links, organizations can significantly improve bandwidth throughput without the price tag of more expensive links.
Cable modems	Like DSL links, cable modems provide greater download speeds than upload speeds, making them suitable for the same types of applications as DSL lines. A significant advantage of combining cable modems with telco-type links such as DSL and T1s, is that the carrier networks are parallel so if a carrier’s network stops functioning normally, the second one will most likely be available to provide failover functionality.
Fixed wireless carriers	Point to point carriers commonly use microwave antennas on the roof the customer site pointing towards a carrier’s point of presence dish. Since the carrier uses no wires, such services are to be considered viable secondary ISPs to ensure maximum uptime, and services can reach up to 100Mbps where available in most cases.
Mobile Networks	By using mobile Internet access such as 3G mobile telephony services, organizations can ensure a lifeline to the Internet or other services should all wired providers no longer be operative. These links do not typically offer static IP addresses but can provide outbound connectivity to mission-critical services. Like DSL and cable modems, these links are asymmetrical and offer more throughput downstream.
WiMax and LTE	These two technologies are considered 4G wireless carrier technologies and are emerging in many marketplaces. They offer performance improvements over 3G networks, and some private operators offer private IP addressing.
Utilities ISP links	Many utility organizations are providing an alternate source of bandwidth distribution, through electrical grids or natural gas pipelines. These alternate ISPs act as an alternative to regular suppliers providing an alternative network for maximum uptime in case of ISP failure.
Satellite links	Satellite links (VSAT) are available in any region of the world, making them a viable choice when geography or local ISPs pose a challenge.