Trial by Fire
On Monday, February 4, 2008, RF Cafe began using the services of a company that provides proprietary DNS IP address lookup
and Internet data packet routing via private "Managed DNS" servers located across the globe in strategic locations (see red dots on image
The prime motivation for subscribing to this service (it is not cheap) is to make visiting RF Cafe as efficient as possible for
you. Efficiency as defined by my criteria is thus:
1) How quickly does a page begin loading after you instruct your browser to fetch
2) How long does it take the page to completely load once started?
3) Does the requested page fail to either begin or complete
The best way to meaningfully gauge the user experience is to ask you, the user. Please take a moment to vote in the poll
below. You do not need to register - just click on the button that best describes your experience. (Poll removed)
I spend a lot of
time surfing the Internet looking for data and links to data or articles to present to RF Cafe's visitors. Being provided with lots of new
and useful content is what (hopefully) keeps you coming back again and again. In my daily quest, I visit a lot of websites; a few are excellent,
the vast majority are OK, and a few are downright atrocious. Page load time is not as big of a deal as it was back when there were still
a lot of unfortunate souls still using dial-up service, but there are still some pages out there (including on RF Cafe) that are so heavy
on content that it can take three to five seconds to fully load. If the slow loading time is due to a lot of large images or due to some
silly animated presentation that only the designer thinks is cool and worth wasting your time on, then unless I really need what is being
offered, I leave the website.
Even more offensive to my fragile psyche is the cursed full-page entry advertisement. I of all people
realize the need for paying advertisers to help underwrite the cost of maintaining a website, but personally think those are going to far.
Particularly insulting are the ones that have the utterly untruthful message saying that the page you really want to see is loading, implying
that the ad is just there so you do not have to watch the page load. ...but I digress.
Believe it or not, I spend a very large fraction
of my waking hours working on RF Cafe. Call it dedication or an obsession, but if I spend time doing anything other than creating content
for the website, I feel as if I am neglecting my duties. Always in the background of my RF Cafe activities is a real concern about how each
change or addition is going to affect the overall quality of the user's experience. Will a busy engineer, manager, student, or even a hobbyist
deem RF Cafe truly useful, or just a waste of time? Having to wait a long time for pages to load is definitely a waste of his/her time, so
that is why I decided to employ a professional service to help guarantee that every requested page is received without errors, and then all
of those in an acceptable amount of time.
I have merely a layman's knowledge of the way the Internet works. The domain name system (DNS) functions within
it to take a browser's request for a certain web page using the alias that is a domain name and converts it to an equivalent IP address,
which is then used to fetch and deliver the page to the browser. While the workings of the Internet are a well-defined and cogent set of
rules encoded in hardware and software throughout the world, the fact that everything works so well (or at all) borders on the miraculous.
Rather than risk constructing my own inept explanation for how this new "Managed DNS" service works to bring
RF Cafe to you in a more effective and efficient manner, I will resort to proving a few snippets of wisdom form the company's website. In
the spirit of Linus Van Pelt when responding to Charlie's famous
question: Isn't there Anyone who knows what "Managed DNS" is all about?
"The network currently consists of a mesh of fourteen (14) globally synchronized
DNS server nodes located on five (5) continents. By utilizing dedicated hardware,
each major component of the system is partitioned to function independently while providing a means of marshaling access control. Hardware
is transparently added to an existing node without negatively impacting service at that node. Once a new DNS server is added, it immediately
begins announcing the appropriate Anycast addresses and is included in the
pool of servers available to answer queries within that node. Similarly, if a server fails, or is removed for maintenance, it ceases announcing
the Anycast addresses, and queries continue to be received and answered by the remaining operational servers in that node with no end-user
Diverse network connectivity is utilized within the network. Primary IPv4 connectivity is provided by three International network carriers. Each node is multi-homed with 100 Mbps (Fast Ethernet)
connections to each carrier. In addition, every node is also connected natively to a global IPv6 network. Finally, each node is connected to the local public peering fabric at that node, with a liberal peering policy.
To ensure robustness and redundancy, a carefully architected matrix of network announcements is utilized to ensure that both minor and catastrophic
failures of any elements within the network will not result in failures of resolution for end users. This includes unique combinations of
network (IP address) announcements, network providers and collocation
facility operators so that the catastrophic failure of an entire backbone carrier, combined with the failure of all facilities controlled
by a collocation operator, would have no material impact on the service levels provided to customers.
The unprecedented internetworking
reliability and minimized resolution latency ****** offers are achieved in part by the implementation of advanced IP Anycast techniques.
The term 'Anycast' describes packets being sent between a single source and the nearest (in terms of network topology) of several possible
destinations in a group, all having the same IP address. Anycast is different from multicast (packets between a single source and multiple,
unique destinations) and unicast (packets between a single source and a single destination).
BGP (Border Gateway Protocol) route announcements from each
node, the system leverages the features of BGP to enable the routing of user queries to a topologically nearby node, resulting in the following
network efficiencies and advantages:
Reduction of network latency for DNS transactions, as compared with a 'standard' deployment
of DNS services. Reduction in the number of queries routed to distant servers, thereby reducing the likelihood of encountering congested
routers. Reduction in the number of query packets that are dropped, and which then result in DNS timeouts/retries. Improved performance and
reliability to the end user. Utilizing Anycast, the same six IP addresses are announced in different combinations from each DNS resolver
in the network infrastructure. This implementation provides additional redundancy in the face of network routing problems that can be caused
by third parties. In the unlikely event that one or more of the IP addresses become unreachable, queries from users are seamlessly directed
to an alternate node, which is also announcing the same IP address.
Anycast allows the geographical distribution of requests to any
available DNS resolver for redundancy to effectively distribute traffic/requests to any given IP address globally, and to increase responsiveness
of the overall system by using the closest (in terms of network topology) available resource to answer any query that enters the system."
... That's what "Managed DNS" is all about, Charlie Brown.
For the time being, I will protect the identity of the company - just in case RF Cafe does not realize the anticipated gain.
Posted January 10, 2008