Optimizing the Corporate Network with WAN Virtualization

Steve:

I believe that one of the most important aspects of this discussion is the status of WAN services. Starting in the mid 1980s, we went through a 20 year period in which we saw the continued evolution of WAN services. They went from T1/E1 TDM networks to Frame Relay to ATM and now to MPLS. There is no successor to MPLS on the horizon. Given the gestation period that is associated with WAN services, that means there will not be a fundamentally new WAN service for the foreseeable future.

That fact, combined with the fact that the WAN is one of the few components of IT that does not follow Moore's law means that in order to control the cost of WAN services, IT organizations must evaluate alternatives such as those discussed in this thread.

WAN Virtualization technology is broadly applicable to almost any company with 5 locations or more, since over time all but perhaps the smallest companies need more bandwidth, are looking to reduce monthly costs and would like greater network reliability and application performance predictability.

That said, we tend to focus right now on the Fortune 301 - 20,000 - i.e. those companies with 10 - 100 locations. This is our sweet spot at the moment. And the more international locations customers have, the more valuable the technology is, since WAN costs outside of North America are frequently much higher. Just as Riverbed and Peribit showed, when selling a two-ended WAN solution, you really need to prove yourself on the 10-20 site networks before deploying the 50 site networks before deploying 100 site networks, before you can think about doing multi-hundreds. The way you manage the solution today is really optimized around that 10 - 100 site size as well. Over time we'll add the additional scaling and especially management tools to make it easier to deploy multi-hundred site networks.

Steve, first an important clarification. We don't typically limit any given traffic flow to a single WAN connection. We make per-packet forwarding decisions, not simply per-flow. This allows us to use all of the available bandwidth even for just a single flow and the overwhelming majority of the time when all the connections are working well. This also means that for delay and jitter-sensitive protocols like RTP or Citrix, we not only put them on the best quality network at flow initiation, we will move the packet flow to a better connection, sub-second, if congestion or link failure causes network quality to get meaningfully worse mid-flow.

Now this said, we do recognize different flows and treat them differently, of course, as does any decent middlebox. We support DSCP and ToS markings, and also support 5-tuple classification (source and destination IP addresses and ports plus IP protocol) to distinguish flows.

First, let's make sure we're using the same terminology. "Application delivery" typically refers to single-ended boxes like those made by F5. We don't compete with them; and in fact, WAN Virtualization is complementary for enterprise intranet uses.

"Application acceleration" typically refers to two-ended WAN
Optimization (i.e., the market in which Riverbed is the leader). While
our technology overlaps with theirs by probably 10% - 15% (more on that
in a second); in fact, WAN Virtualization is also complementary to WAN
Optimization. About two-thirds of our customers use WAN Optimization.

While both WAN Optimization and WAN Virtualization solutions can answer
the problem of more bandwidth--WAN Optimization frees up bandwidth on
existing private WAN links, where WAN Virtualization allows you to
aggregate existing plus inexpensive Internet bandwidth, and utilize the
aggregated bandwidth more efficiently--when it comes to application
acceleration, WAN Optimization and WAN Virtualization "excel" at
different things.

The two most important capabilities that WAN Optimization offers are
disk-based data streamlining/deduplication, and application-specific
support for Microsoft CIFS, the one protocol which really is "broken"
on the WAN. WAN Virtualization's bandwidth aggregation, loss
mitigation, sub-second switching and unique ability to deliver high-quality, real-time support even over the public Internet, are things which WAN Optimization doesn't do.

Customers have already started to widely deploy WAN Optimization for
data center consolidation projects, and it delivers "unbelievable"
speed-ups for "warm" transfers--files which have previously been
accessed over the WAN for which the disk-based data deduplication
delivers truly LAN-speed results--and substantial speed-up for CIFS
file access overall. Talari's WAN Virtualization, by contrast,
accelerates getting those huge files to a remote site much faster the
first time ("cold transfers") with its bandwidth aggregation
capability. The loss mitigation and sub-second switching mean it's the
ideal solution for the "works pretty well most of the time, but
occasionally performance is terrible" problem that is almost always a
network congestion issue. WAN Virtualization can improve the
performance of VDI/Citrix-type applications, where the highly optimized
protocol can't be improved much by WAN Optimization. And WAN
Virtualization makes the network more reliable, and can enable higher
quality VoIP, videoconferencing and video streaming even when using
inexpensive Internet connections.

Ipanema's HNU performs even with encrypted flows, like SSL for example. Application classification, Control and dynamic WAN selection work over encrypted flows without sharing any confidential information between our system and the customer's IT. For WAN optimization to combine with HNU, the customer must activate the SSL acceleration feature (soon available).

So long as you have diverse networks at each location (and 2 is completely sufficient), delivering high quality VoIP over public Internet links is completely reasonable. We have many customers doing just that. We've done it ourselves for our internal communications for more than 2 1/2 years now. Our development team in North Carolina and our outsourced QA team in Bangalore, India use this daily, and in India they have only the least expensive local, highly oversubscribed DSL links.

We have two different techniques which enable highly reliable real-time application support. The first is pretty much the same as what we do for TCP traffic: namely, in addition to putting the real-time flows on the best path between locations with the lowest loss and the lowest jitter, we will quickly switch the flow, sub-second, to a better path in the event of network congestion related severe packet loss or even just high jitter. This alone will result in hiqh quality voice, where occasionally a word or two might be missed, much as might result from, say, a quarter second of static on a mobile voice call.
By turning on replication for such voice flows, we will actually replicate the packet stream on two different paths, as unrelated as possible in terms of first mile and last mile links, and suppress the duplicate at the other side. In this way, even if what had been the best path starts experiencing 50%+ packet loss, or say 190 ms burst of jitter, the packets show up a few milliseconds later on what had been the slower/worse path, and the application never misses a beat. We count on their being jitter buffers in the clients, but in fact that's exactly how VoIP and videoconferencing works. In this way, we deliver "platinum" quality VoIP, better than the best MPLS network - including MPLS with QoS - can deliver.

Video can also run over Internet links the same way, with one important caveat: there needs to be sufficient available bandwidth. In particular, each link at a site with only two WAN links must have sufficient bandwidth to support the desired video session, in case congestion or link failure causes a problem with the other link

For resiliency reasons, we recommend several ISPs (MPLS and/or Internet). Ideally the split should include wiring to POPs in order to limit the probability of severe simultaneous incidents. On the other hand, there is nothing that prevents a customer from having the same ISP in a branch, or different ISPs end-to-end (it is generally the case as ISPs have only a local reach): HNU will perform well and automatically deliver the best of the combined network.

Ipanema's HNU works at the flow level. Among its many different advantages, this allows for the selection of the best network interface from a site even if the remote site is not equipped by a physical (or a virtual) appliance. The flow back from the remote site will be normally routed.

Our solution is designed to pay for itself in less than a year versus buying more North American MPLS bandwidth or replacing your MPLS connection. The more international locations there are, the faster the time to cash breakeven, in the range of 5 - 8 months.

This is just the "hard" cash return, of course. In addition customers have a lot more bandwidth: 4 - 10x is typical. And of course greater reliability and application performance predictability. This adds "soft" ROI in terms of avoidance of downtime and lower IT costs in terms of troubleshooting, and of course the "softer" still return from ensuring that end users maintain a good application experience. Unlike other companies, because the benefits are so compelling, we're able to focus only on that "hard" ROI. We're not looking to take money from the Cisco equipment budget - nor the WAN Opt budget for that matter - but rather from the AT&T/Verizon/BT budget.

Steve: just two small points here. We'd classify Ethernet-based VPLS as simply another variant of MPLS as far as WAN Virtualization technology is concerned. In fact, any kind of private IP networks–including point-to-point TDM connections and customers' internal privately built MPLS networks--are the effective of MPLS or Frame Relay to WAN Virtualization. We simply usually refer to service provider MPLS networks when referring to the private WAN simply because these are the most common used by our customers.

Talari's WAN Virtualization technology does for enterprise WANs what RAID did for storage--delivering a network with 30 to 100 times the bandwidth per dollar, ongoing WAN costs reduced by 40 to 90 percent, and greater reliability than existing corporate WANs--bringing Moore's Law and Internet economics to enterprise WAN buyers for the first time in more than 15 years. By continuously measuring end-end across all network paths and switching sub-second when network performance problems occur, our WAN Virtualization technology turns the weakness of the network-of-networks that is the Internet into a strength, enabling customers to cost effectively augment or replace their MPLS WANs without having to sacrifice reliability or application performance predictability.