Along with MPLS, companies are increasingly using the Internet as the access technology for connecting locations to the company networkhowever the quality of the network on the Internet is not always up to standard.
One might think that in the future, company networks will only need the Internet for data transmission. After all, the Internet is increasingly being used as an access technology for company networks, a domain that is currently dominated by MPLS technology. That's because prices for Internet data traffic have been dropping for years, even as the available bandwidth continues to rise. TTherefore, using the Internet to access the wide area network (WAN) is a promising approach to reduce operating costs. As a result, productivity at the involved locations becomes dependent on the high availability and quality of the Internet connections. Guaranteeing performance is not a simple task, because there ares inherent obstacles to the Internet VPN access concept: the "best effort" principle.
"I’ll do my very best."
Best effort means: the Internet transfers data packets as fast as possible. If transmission capacity is exhausted, congestion can occur. Such peak loads are not just local or at specific times of the day; they can also be caused by major events. During the 2016 Euro Cup soccer final, for example, Akamai, a content delivery network provider, transmitted a peak value of 7.3 terabits per second for video streams – enough data to fill nearly 200 standard DVDs, every second. Moreover, Internet traffic cannot be prioritized and transferred with a defined level of quality – like MPLS allows. This can result in connection problems in delay-sensitive applications such as video and voice.
Internet in the proper dosage
Market research company Nemertes wanted to find out just how many companies use WAN access via Internet. To do so, their analysts surveyed IT experts from 200 companies, more than half of them in the international domain. The results: companies with more than 2,500 employees connect on average one-quarter of their sites with the Internet only; the figure for SMEs is 14 percent. However, the companies with the most successful WANs only use Internet VPN access exclusively for five to ten percent of their locations. Therefore, Nemertes makes the following recommendation: "Use Internet-only connections sparingly. Relying too much on the public Internet could be counterproductive, since [...] you share the bandwidth with public data traffic."
More quality on top
Price Development and Reliability of Internet Connections
Price development and reliability of Internet connections 1998-2015 (figure based on the White Paper "Hybrid networks"). Source: DrPeering.net
One option for solving this best effort problem is overlay networks. While they are also based on Internet connections, they use additional technologies to coordinate and optimize Internet traffic. T-Systems for example provides such an optimized Interne VPN access based on Akamai Technologies. The data uses an IPSec tunnel through the overlay network for most of the way. The network directs the packets over lines with the lowest packet loss and latency – which is usually the shortest route. If longer distances are involved, the packets are replicated and sent toward the company network over different paths. Only the fastest packets are forwarded to the WAN. This improves quality in particular over long – intercontinental – distances. The special routing drastically reduces packet loss and also cuts latency times and jitter.
Although an Internet overlay network cannot raise network quality to MPLS levels, it can still be sufficient for the requirements at hand. This applies, for example, to smaller locations for which an MPLS connection is not cost effective or where MPLS connections are not available.
Bottlenecks between networks
A further quality factor in WAN access via Internet is peering – that is, the exchange of data between different operators' networks. Depending on the Internet service provider involved, the data can pass through several operators' networks between the local site and the company network. If the lines to these Internet exchanges do not provide enough bandwidth, bottlenecks can occur. This risk increases with the number of peering points. Some regional providers even have to rely on peering within a country. Therefore, global companies should use a major Internet service provider that has international, high-bandwidth connections to other major providers.
Due to its constraints, the Internet is unlikely to replace MPLS as the company network standard. However, companies will increasingly use Internet connections to cut costs when connecting their locations (see the article "Two pillars for the company network"). In the future, experts will increasingly discuss which new role Ethernet can play in wide area networks. After all, this technology can be built on top of IP infrastructures, giving it entirely new capabilities. We will examine this in more detail in one of the following articles.
If companies switch to SIP trunks, they should consider a PBX (private branch exchange) and a centralization of all connections as well. It is a decision that will save them more than just voice channels.