Wireless Service Providers → Re: redundant wireless links

AFAIK, there are no commercial product that address this exact problem. There are some multi-WAN routers which come close but their WAN throughputs are designed for DSL/Cable.

Curiously my old company developed a solution for truly transparent trunking of mismatched parallel links many years ago. It was originally designed to parallel a FSO link with a 5Ghz PtP, but I made it generic enough for upto 4 links of any kind and any throughput.

The prototype was developed on a really expensive off-the-shelf PCI board which had a Xilinx FPGA driving 4 10/100 ethernet ports. Sadly, my company ran out of money to make a lower cost FPGA board for commercial product.

The FPGA is essential to implement the low latency scheme to merge the links transparently. I will check if there are affordable PCIe FPGA boards with quad gigabit ports and adapt my solution for today's high throughput PtP links.

Any switch that does LACP can do this.

Also known as Port Channel in Cisco land.

But, you need to make sure that your radios will pass L2 PDUs transparently else this will probably not work.

Other things to consider when using LACP are source and destination MAC and IP addresses of your traffic, and the hashing algorithms available on your chosen switches to make sure you can get some useable load balancing out of them.

Curiously, I was motivated to develop the custom FPGA solution because of my in-depth knowledge of 802.3ad from the 1990s. The following news release is from April, 1998 ... when I was working at Plaintree Systems, which was a pioneer in Ethernet switching and link aggregation.

»www.thefreelibrary.com/I ··· 20533512

In multi-vendor tests sponsored by Sun and conducted by an independent testing organization, The Tolly Group, Plaintree's WaveSwitch(TM) 9200 interoperated smoothly with Sun's servers.

...

What is Trunking

Trunking, sometimes called link aggregation, combines multiple links into a single, logical trunk. The individual links share the traffic load. This results in increased bandwidth and increased survivability. If one or more links in the trunk are disabled, the remaining links continue to operate.

P.S. Plaintree suffered same fate as other Canadian tech pioneers ... Nortel a few years later and most recently Research in Motion.

*** Well, it seems every company is trying to improve on the IEEE standard.
»en.wikipedia.org/wiki/Li ··· regation

In addition to the IEEE link aggregation substandards, there are a number of proprietary aggregation schemes including Cisco's EtherChannel and Port Aggregation Protocol, AVAYA's Multi-Link Trunking, Split Multi-Link Trunking, Routed Split Multi-Link Trunking and Distributed Split Multi-Link Trunking, ZTE's "Smartgroup", or Huawei's "EtherTrunk".

Most high-end network devices support some kind of link aggregation, and software-based implementations – such as the *BSD lagg package, Linux' bonding driver, Solaris' dladm etc. – also exist for many operating systems.