Wednesday, June 18, 2014

Internet and WAN Connectivity - WTF are all these terms?

As we are all aware, the ICT (Information and Communication Technology) industry seems to exist solely to create new TLAs (Three Letter Acronyms) and ETLAs (Extended Three Letter Acronyms) and one of the most confusing places that these TLAs and ETLAs are used and abused is relating to networking in general and more specifically to Internet and WAN (Wide Area Internet) connectivity. So, I'll make an attempt here to help and clarify this a bit...

There are many ways to break Internet and WAN connectivity down, however there are two main types of Internet connection available today – asynchronous and synchronous. ADSL (Asynchronous Digital Subscriber Line), ADSL2 and ADSL2+ are all asynchronous connections – they have a faster download (inbound) speed than upload (outbound) speed. ADSL speeds are generally available up to 8192Kbps down and 384Kbps up and ADSL2+ speeds are generally available up to 24Mbps down and 1.2Mbps up. There’s also an ADSL2+ Annex M standard that is available in maximum speeds of around 20Mbps down and 3.2Mbps up. All these speeds are "best case" and basically will only be achieved if you are located in a building next to a telephone exchange, with these speeds dropping off as the distance from the exchange increases.

A business grade ADSL2+ service with 200GB or so of data is likely to cost in the vicinity of $100-$150 per month.

ADSL and ADSL2+ connections can also be configured to sacrifice a lot more of their download speed for increased upload speed, hence the availability of ADSL connections at 0.5Mbps/0.5Mbps and ADSL 2+ connections at 2Mbps/2Mbps. As you can see, these speeds are now synchronous, yet still delivered over one form of ADSL connection - way to help keep things clear...

Synchronous connections are delivered in 2 main formats – over copper or over fiber. Fiber connections can go faster (up to 1Gbps and higher), but the installation costs can be in the region of $5000. Synchronous connections over copper are generally available up to 40Mbps and are often referred to as “Ethernet in the First Mile” (EFM), “Ethernet Over Copper” (EOC) and “Mid-Band Ethernet” (MBE) and these terms are, to all intents and purposes, interchangeable.  Installation costs on an EOC connection are in the region of $1200.

A 10Mbps EOC connection with 200GB or so of data is likely to cost in the vicinity of $250-$500 per month, and on Fiber this will likely cost around $500-$750 per month depending on the service provider and the distance from the exchange.

Historically, asynchronous connections were more than acceptable for most individuals and businesses as most of the time people were *downloading* things like files and web pages from the Internet and rarely *uploading* information, but as time has progressed this has become more the exception than the norm for many businesses as they are using online storage for documents, photos and so on, online email and groupware servers and connections between multiple offices. This is where synchronous connections have become more popular for businesses.

The National Broadband Network (NBN) here in Australia is a bit of an odd one out. It is an asynchronous connection, but delivered at speeds of up to 100Mbps down and 40Mbps up – so it delivers very decent outbound speeds, with even faster inbound speeds. Of course, this is for those lucky enough to have had this rolled out before the Federal Liberal/National Party decided that high speed Internet was too scary - people get easy access to educational material - and destroyed Australia's chance at decent Internet speeds.

A 100/40Mbps NBN connection with 200GB or so of data is likely to cost in the vicinity of $120-$170 per month, depending on the service provider and extras included in the plan.

Now, just because you have an ADSL2+ or EOC connection doesn't necessarily mean it is connected directly to the Internet. Many larger, geographically diverse businesses will have an ADSL2+, Fiber or EOC tail connected to their multiple locations that are all brought back into their ISP's network and from there, connected to the Internet. This is the "WAN" part of the "Internet and WAN" in the article title. These sorts of connections are often referred to as an MPLS (Multi-Protocol Label Switching) Network, VPLS (Virtual Private LAN Service) Network or simply a Private Network.

Another way to interconnect multiple locations is across the Internet using a VPN (Virtual Private Network). This is where each site is connected directly to the Internet and across this Internet connection is run a secure pipe (the VPN) that connects the multiple sites. Types of VPN connection include EoIP (Ethernet over Internet Protocol), IPSEC (Internet Protocol Security), L2TP (Layer 2 Tunneling Protocol), PPTP (Point-To-Point Tunneling Protocol) and SSTP (Secure Sockets Tunneling Protocol).

Another term you may have heard is "Contention Ratio". What this means, basically, is the number of customers of a particular ISP (Internet Service Provider) who are sharing the bandwidth that you are paying for. So, if you see a 1:1 contention ratio, this means that the speed of the connection you are paying for is reserved for you into the ISP's core network. A contention ratio of 4:1 means that you're sharing that bandwidth into the ISP's core network with 3 other customers. Residential contention ratios are significantly higher than those for business customers, which is one of the reasons that residential connections are priced lower than business grade connections.

Finally, you may have heard the terms "Layer 2 Connection" or "Layer 3 Connection" which are a little more complex to explain as compared to the previous terms, however the simple way to look at it is a L3 Connection will have all traffic from the ISP's network sent to you at a single QoS (Quality of Service) level - you can't ask for inbound VoIP (Voice over Internet Protocol) to have higher priority than general web browsing, email, file downloading or anything else. A L2 Connection will allow you to have inbound traffic prioritized from the ISP to your network, so a large inbound email won't stomp on a VoIP call from a potential client. This may help explain why L2 Connections are often a little more expensive than a L3 Connection.

So, back to the big question - what do I want and when do I want it?

If your Internet requirements don't involve a lot of VoIP, video conferencing, Private Network, VPN or general outbound traffic, an ADSL2+ service will likely suit quite nicely. However, if you do utilise VoIP, VPNs to other sites or remote workers, video conferencing or have various cloud-based services such as hosted email, hosted file services or have a requirement for a better SLA (Service Level Agreement) than "we'll try to get it running again... sometime", some form of EoC or Fiber network connectivity (Internet or WAN) would likely be a better option.


The Outspoken Wookie

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