[Bp_ipv6] Can we do the math? ( was [MEAC ICANN] Fwd: Interesting IPv6 metrics)

Marco Hogewoning marcoh at ripe.net
Thu Aug 25 08:18:10 EDT 2016

(This may not reflect my employers opinion or even reality as a whole)


Exec summary: 5 year ROI on IPv6 for a larger-than-life mobile carrier in the US can be gestimated at 225 million USD.

Disclaimer: I might be off by a zero or two (factor 10/100) as a result of assumptions or flaky math :)

Can’t find the original email on this thread, but somewhere Jan wrote:

> I asked Cameron Byrne from T-Mobile USA how many mobile devices do they 
> have now on their network using IPv6 connectivity and his estimation was 
> around 48 million.
> Cheers, Jan

Was chatting with Silvia the other day, wondering if we can piece it together….

Curious mind wants to know:

- How many customers are in this network?

The answer (Q2 financial reporting) is 67,3 million (call it 67 for ease)

We have them apparently also on record saying 50% of the traffic is IPv6. This doesn’t say much unless we know:

- How much traffic is on that network?

Now, this needs a bit of reading between the lines and guessing, but the Q2 investor report has one interesting bit where they brag on quality:

	"In the second quarter of 2016, T-Mobile’s average 4G LTE download speed was 22.4 Mbps compared to Verizon at “

So the average customer has 22 Mbps, and 67 million of them ((22*10^6) *( 67 * 10^6)) gives around 1,5 petabit/s, which is a rather big number

In fact unlikely that all of them are pushing 22 mb _all_ of the time and I guess we can figure in some oversubscription. Conservative estimate of 1:1000 would bring the total average traffic down to 1,4 terabit/s, 50% of which is IPv6 :) (more likely the overbooking is a factor 10 higher, but let’s stick to this).

- How much does this cost to transport that amount of bits?

We don’t know the number for T-mobile, but we have a credible source in Swisscom:

	http://www.swissipv6council.ch/sites/default/files/docs/map_martin_gysi_ipv6_council.pdf says difference is 6350 CHF.

So, passing 1 gb/s through CGN costs 8300 USD, shipping the same amount of traffic on IPv6 is only 1700 (which btw is 5 times, cheaper, not 6 as often claimed by hearsay on social media).

Putting this all together:

If 50% of the traffic (0.7 tbit/s) really has moved, the cost saving in transport is in the order of 4.6 million USD per month at the current rate.

Now of course this meant that a) the had a huge spend on IPv6 b) started with zero return. But still ever since they started to roll out, they have been collecting some money back from the first IPv6 bit shipped.

I’m too stupid to figure out how to get Excel to model this across the past 36 months, but if I am not mistaking in lineair (which it isn’t) you end with 86 million.

Last question remains: 

- How much did it cost them and is 36 months a reasonable ROI?

Or can we extend to 5 years (at which point you are around 225 million USD).

- Is 225 million a reasonable cost estimate to get a network with 70 million users to IPv6?


More information about the Bp_ipv6 mailing list