These original Kirt's Cogitations™ may be reproduced
(no more than 5, please) provided proper credit is given to me, Kirt Blattenberger.
here to return to the Table of Contents.
Cog·i·ta·tion [koj-i-tey'-shun] – noun: Concerted
reflection; meditation; contemplation.
Kirt [kert] – proper noun: RF Cafe webmaster.
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 below).
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 it?
2) How long does it take the page to completely load once
3) Does the requested page fail to either begin or complete loading?
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
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)
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
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 impact.
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:
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,
For the time being, I will protect the identity of the company - just in case RF Cafe
does not realize the anticipated gain.