Welcome to the second entry in this series on “wargaming” WAN scenarios to make sure you’re getting the most bandwidth bang for your buck.
If you didn’t read the set-up to the series, please go back and check that out. This will all make a lot more sense if you do.
The first actual scenario we’re going to tackle is adopting local internet breakouts in an MPLS-DIA hybrid WAN. Let’s dive in.
Many WAN managers we talk to have already begun implementing local internet breakouts, even before SD-WAN adoption.
A recent interviewee from our 2019 WAN Manager Survey—which is coming soon to a browser near you—explained that their adoption of local breakouts with DIA was a result of changes in compute and security. “[W]e used to be a Citrix house connecting a hosted desktop environment to the data center—and the internet was in the data center, in that case,” they said. “But we changed to Windows 10 desktops and mobile devices, which meant [that] backhauling to the data center didn’t make sense anymore. So we implemented breakouts in all of the offices. The other component of that is Zscaler, which provides our security layout for that.”
"We changed to Windows 10 desktops and mobile devices, which meant [that] backhauling to the data center didn’t make sense anymore. So we implemented breakouts in all of the offices."
Another 2019 interviewee mentioned that network service to their sites in the U.S. frequently went down. According to this interviewee, an auto accident might take out an entire site or local construction will cause an outage. Similarly, carriers will relocate circuits and fiber pairs to be more diverse. "This has happened a lot with [carriers]," they said. "They say they're mandated by a bridge law to move circuits."
While compute and physical diversity are concerns, getting the most bandwidth for the lowest price is certainly a motivator, as well.
"I didn’t feel our telecom [spend] before MPLS was out of whack, but we more than tripled our intranet bandwidth, got our internet up 40 times, and we are doing it for six figures less a month.”
One of our interviewees from our 2018 survey indicated that moving to local internet breakouts with DIA was mostly a most-bandwidth-for-the-best-price move. “We were dedicated to tripling our intranet bandwidth, our internet capacities would go up 40 times, and we would do it at the same price,” said this interviewee. “We had always been pretty tight with telecoms. We would threaten an RFP every half a year and used benchmarking services like TeleGeography. I didn’t feel our telecom [spend] before MPLS was out of whack, but we more than tripled our intranet bandwidth, got our internet up 40 times, and we are doing it for six figures less a month.”
To distill these ideas into some quick lessons about why we see WAN managers shifting from all-MPLS to MPLS-DIA hybrid WANs:
So, here in our first scenario, we’re assuming that local internet breakouts are DIA, not business broadband. DIA is the carrier-grade internet answer to MPLS VPN and, unlike business broadband, it’s always symmetrical, uncontested, and comes with carrier-grade SLAs.
But is it actually cheaper?
We get this question a lot, especially from customers who might have heard that—at least at a best efforts CoS—MPLS VPN and DIA prices had largely converged. I won’t make you wait, DIA is still cheaper than MPLS, though the amount varies by location and port size.
Let’s see how it works in a realistic WAN scenario where we boost the available site capacity.
To test out the MPLS-DIA hybrid WAN we made five changes to the Original MPLS WAN:
These changes resulted in a network that had many MPLS and DIA ports in the 5-10 Mbps range, but are added together for double the site capacity.
For example, if a site has 10 Mbps of MPLS VPN and 10 Mbps of DIA, the total site capacity is 20 Mbps. There are still quite a few ports in the 51-100 Mbps range, as well. The average total available capacity per site ended up almost doubling from 125 Mbps in the original network to 241 Mbps in the new one.
How Did We Change Capacity Ranges from the Original MPLS WAN?
Original MPLS WAN Site Capacity Range
MPLS DIA Hybrid WAN Site Capacity Range
Much of the capacity increase was in the U.S. & Canada, Western Europe, and East Asia, where the headquarters and data center sites are located.
Only sub-Saharan Africa had the same average site capacity.
How Does Average Site Capacity Change by Subregion?
MPLS-DIA Hybrid WAN Average Total Site Capacity by Subregion
That increase in capacity came at a price.
The resulting annual total cost of ownership (TCO) is 48% higher than the original MPLS cost. Keep in mind this represents a nearly 100% increase in capacity. The chart shows that, while MPLS costs go down and DIA costs increase slightly, it is access that really contributes to the higher TCO.
How Does Adding Capacity With DIA Affect the Total Cost of Ownership
Original MPLS WAN & MPLS DIA Hybrid WAN Annual TCOs
What if your DIA service was on-net and did not require an access line?
When we first started tracking DIA in 2006 carriers exclusively sold it as a “port-based” product with an additional charge for local access. However, in the past several years, many carriers and ISPs have started to sell DIA as a bundled service when it is “on-net,” or in a building in which they have a presence. Particularly for those customers that are in downtown areas, multi-tenant office buildings, office parks, or other locations where there are likely to be competitive carriers, it is increasingly common to be able to get on-net DIA service without any additional local access charge.
Particularly for those customers that are in downtown areas, multi-tenant office buildings, office parks, or other locations where there are likely to be competitive carriers, it is increasingly common to be able to get on-net DIA service without any additional local access charge.
Also, in some cases, carriers source on-net DIA from an aggregator and pass on that pricing. The port charge we show is equivalent to the total charge in these cases. The access portion of a DIA site cost can range from 25% to 75%—or more—so if you can buy on-net DIA service, you will likely save considerably.
With that in mind, we re-ran this exact scenario, but took out the access lines in regions and locations where it seemed feasible. We left access lines in place in Africa and remote sites (16-50 km access distance band or above) and removed the others. About 25 sites ended up keeping access lines to DIA.
What Happens When We Increase Capacity Using Mostly On-Net DIA?
Original MPLS WAN, MPLS DIA Hybrid WAN, & MPLS On-net DIA Hybrid WAN Annual TCOs
It shouldn’t be surprising that this network, while still nearly doubling available site capacity, increases the TCO much less at 13%. While increasing site capability to handle SaaS, streamlining security by moving it out of the data center, offering sites increased protection from outages, and significantly increasing available site capacity we’ve only increased the TCO moderately. Not bad!
Next time we’ll look at local internet breakouts using cheaper (but perhaps less reliable) business broadband to see how we might do these things while still lowering costs.
Next up: