The core of the Internet is based on a plethora of peering agreements between the various carriers that transport IP traffic. These peering relationships are... Read ›
Why Carrier IP Peering is a Major Issue for Real-Time Traffic The core of the Internet is based on a plethora of peering agreements between the various carriers that transport IP traffic. These peering relationships are complex both financially and operationally. Peering disruptions, as recent events show, can significantly impact UCaaS and other real-time cloud traffic delivery.
Peering Problems Impact Peering Partners
For example, in my No Jitter article about cloud availability issues, I discussed a number of events reported on downdetector.com that give insight into the challenges of operating cloud solutions. One event was a RingCentral outage on April 3. The outage was one of several outages in that timeframe.
In discussing the issue with Curtis Peterson, RingCentral's SVP of Cloud Operations, he indicated that at least a previous outage impacting RingCental users on March 15, 2018 for about six hours was, in fact, caused by Comcast peering issues with certain other carriers. This had a significant impact on the ability to provides services and complete calls for UCaaS users on Comcast. While it was documented on RingCentral, the issue would have impacted any real-time traffic peering to Comcast.
Peering issues can also be specific between carriers and not across all of the peering paths. For example, a new release of software for routers in Carrier A has an issue with the router software in Carrier B. The result is a significant degradation in capacity and latency across the peering connection. However, connections to Carrier C that uses the same router vendor as Carrier A will continue to work. If the issues are intermittent, routing protocols may put real-time sessions into that path even though there are real-time performance problems with that path.
What SD-WANs Can Do About Peering Problems
The challenge is that there are few ways to either determine or react in real time to an issue like this if the paths are constrained by the Carriers and their routing agreements. By deploying an SD-WAN solution, the underlying issues in the path can be identified and analyzed. Connections can be moved to paths that are built on other peering relationships that are not impacted.
A core capability of SD-WAN solutions is the ability to determine on a flow path any issues. Advanced SD-WAN solutions include specific analysis for real-time characteristics like latency and jitter. This enables the identification of paths that include peering points that may be having issues. As virtually all carriers have multiple connections to other carriers, this assures that any paths impacted by peering can be avoided.
An OTT SD-WAN provider, like Cato Networks, includes a private interconnect as well. The private interconnect routes traffic between the PoPs over a private transport interconnect. This further reduces the impact of peering by generally avoiding any intermediate peering connections. This is especially important if the session path is international or across regional geographies that have different major IP Access Providers. A private interconnect can avoid core internet peering issues as well as congestion.
My Take
For organizations and leaders looking to optimize their organization use of technology and reduce cost, deploying an SD-WAN is an ideal way to provide value. SD-WAN solutions minimize the issue of peering disruptions while optimizing other issues. Clearly, discussing the range of peering is something that should be discussed when selecting an IP access provider. With an advanced SD-WAN and an access provider with the right connections, the use of the Internet for real-time is much more reliable.
As I discussed in my previous post, real-time traffic has two characteristics that are challenging for the Internet. First, as the packets have a limited... Read ›
How Route Diversity in SD-WAN Provides MPLS-Like Determinism Required for Real-Time Traffic As I discussed in my previous post, real-time traffic has two characteristics that are challenging for the Internet. First, as the packets have a limited time value and cannot be re-transmitted, any significant change in the transport and packet delivery has the potential of being audible (or visible in the case of video) to the participants. And, as most real-time conversations last orders of magnitude longer than most other types of internet interactions, the probability of a network incident impacting the packet transmission is dramatically higher. The result is that real-time traffic needs a deterministic transport with minimal latency.
The challenge is that in the network world getting Service Level Agreement (SLA) determinism generally has a steep price. Whether a dedicated wire or MPLS, the cost of traditional WAN technology increases in direct relationship to determinism. SD-WAN solves this very problem by utilizing route and component diversity made feasible by the improvements in technology and the affordable costs of Internet bandwidth.
The basic concept of SD-WAN is the concept of route diversification. The two SD-WAN edge points (the point between the Enterprise LAN and the carrier WAN) create multiple route paths between them. For example, in the diagram, each of the red paths represents a different route between the SD-WAN node on the left and right. When the actual traffic arrives at the SD-WAN node, it can decide, based on a factor such as traffic type or current route performance, which route to put the actual data packets into. All of this can be controlled by the SD-WAN controller that oversees the operation.
While the diagram shows a simple premises SD-WAN, the addition of Points of Presence (POP) in a core cloud SD-WAN enables management of the paths between the POPs. This can enable enhanced determinism as much of the variation in Internet traffic delivery happens in the core that is bypassed by having a cloud core. We will discuss this specific topic in a future post.
The benefits to real-time traffic are clear. In the traditional network, if the path that is currently being used for the real-team session flow is impacted, whether through failures or peering issues that limit capacity, the user traffic will stay in that route and the quality of the real-time interaction traffic may be compromised. In the SD-WAN, the traffic can be dynamically moved from the impacted route to the best route available at that time. Through this mechanism, an SD-WAN has the potential of using the best possible route at any point in time between two locations on the Internet, all of the while using the lower cost service of the open Internet, assuming there are sufficient paths for route diversity.
The result is that SD-WAN changes the determinism and cost model of the modern WAN. because of route diversity and path management, SD-WAN enables the MPLS equivalent determinism required by real-time traffic at close to the open Internet cost model. At the core, the concept is simple, but there are many layers of complexity and value that must be considered as part of a well-engineered SD-WAN solution. For example, the routes must be monitored for their current transport characteristics, the traffic type of flows must be determined, the different flows and their relative policies must be included, and more. All of these are critical for VoIP and other real-time traffic.
In considering an SD-WAN solution, there are a number of factors that should be evaluated if optimizing real-time traffic. Whether the SD-WAN is implemented as a premise or cloud solution is a consideration. If backhaul is required and the use of Points of Presence can also have an impact. Also, how the SD-WAN classifies the traffic — this too can have a major impact on real-time determinism. Other considerations like cloud Software as a Service (SaaS) access and security are important. Over the next few months, we will both discuss how to use SD-WAN, but also some of those key characteristics and capabilities that an SD-WAN solution must have to maximize value to real-time traffic.
