FTTN – Network Design Rules highlight backhaul issues

Highlighted by Kenneth Tsang’s blog, it appears that the revision of the NBN Network Design rules could prove to be quite restrictive in terms of the end result being experienced by residents:

Analysis of the latest Network Design Rules for the NBN, dated 30th June 2015, reveals that customers may only be able to reach a committed information rate (CIR) of roughly 5Mbps on a fully loaded node – far short of the 25 mbps that popular internet streaming service Netflix says is required for 4K video streaming and also falls short of the Vertigan panel’s recommendation that 50% of Australians will only need 15 Mbps by 2023.

It also shows that during peak times (particularly after school and evenings) there is potential for degradation of internet speeds due to backhaul congestion/contention:

Taking all of the above into consideration, in a worse case scenario on a  fully-loaded node at peak hour, customers may only reach 5 Mbps if all traffic was distributed evenly:

Number of DSLAM ports	Fibres used for uplink	Entire node’s effective uplink (Mbps)	Committed Information Rate (CIR, Mbps)
48	2	2000	41.7
192	2	2000	10.4
384	2	2000	5.2

 

And also:

Without causing massive disruption to all customers connected to the current node, it may not be possible to transition to FTTP on high-capacity nodes other than by rolling out the network from scratch again.

This again demonstrates the need for a planned and structured design to accommodate for the estate.

Steve

Gleneagles Estate NBN Committee