I have a client with a local area network with about forty client PCs. A few months ago, a third-party phone vendor added an Elastix “PBX” phone server, as well as a new workgroup router. Elastix provides a graphic administrator interface to its underlying Asterix telephone private branch exchange (PBX). Elastix and Asterix run on a Linux server.
The client has complained that phone callers’ voices have been randomly distorting, incoming calls randomly terminating, and after ringing, desktop phones’ handsets randomly die. The phone vendor assured my client that the new router (an Asus RT-N66U) was not at fault, and suspected that the problems were caused by cabling problems or configuration problems with the Elastix server.
After months of frustration, the client asked me to have a look. I began with the workgroup router. I noticed that it was configured to use cut-through switching. (Asus calls this “NAT Acceleration”, which sounds like a good thing, doesn’t it? NAT is Network Address Translation. The router apparently defaults to cut-through switching mode.) VoIP (Voice over Internet Protocol) uses UDP (User Datagram Protocol), rather than TCP/IP. UDP is used for streaming real time audio and video because of its low overhead and potentially reduced latency. It does, though, require that its underlying transport mechanism be rock solid.
Cut-through switching does NOT provide a rock solid transport mechanism! Cut-through switching is fast, but it can damage frames and forward previously damaged frames. The more conservative store and forward method ensures that all frames that traverse a switch remain undamaged. It also will not forward damaged frames. Result? A cleaner network.
Onion layer 1
Troubleshooting system problems is like peeling an onion. You remove one layer at a time and look for changes.
For our first layer, I reconfigured the workgroup router so that it employed store and forward, rather than cut-through switching. Then I waited for user reports. Users reported that we’d fixed the distortion problem, but calls occasionally dropped and/or weren’t initiated.
Onion layer 2
Next, I activated the workgroup router’s QOS (Quality Of Service) feature. I assigned highest priority to all traffic in and out of all active ports on the Elastix server. Then I waited. Users reported that all phones now work as they should.
Think before adding boxes
Adding boxes to networks often works with little tweaking. Eventually, though, services begin to fail and users complain of slow response, as traffic jams the network’s pipes. Eventually, someone must reduce unnecessary traffic, and assign priorities to different classes of network traffic. I recommend doing this before problems occur — not after.
My first email experiences were using CP/M based communication programs (written in 8080 assembler) such as MODEM7 and Mex to reach dial-up BBSs with hosted email systems, around 1980. Many BBSs allowed their users to exchange messages with other users of that BBS. They stored all messages on the BBS host; users viewed and edited messages while their own computers functioned as terminals. These systems didn’t reach beyond the BBS — users could email only other members of the same BBS.
My modem remained off-hook during message reading and editing, so phone bills shot through the roof if the BBS wasn’t within my local calling area. Another drawback was that each BBS program’s email program presented its own unique user interface.
When I signed up with MCI Mail in 1983, my email scope grew. It presented a text-based interface to its terminal-based users. MCI Mail included a gateway to the U.S. Postal Service, and MCI added more gateways later. I liked MCI Mail, except for its pricing. (Was it really a dollar per message? I forget.) Its addresses were ten-digits (I think). I’d dial into their modem pool at 300 bps or reach them via Tymnet while my Northstar Horizon and its Hazeltine 1500 terminal worked as a dumb terminal.
In 1984, Tom Jennings and John Madill lashed up a dial-up network for BBSs (Bulletin Board Systems), called FidoNet. Each BBS would gather up a day’s outgoing messages, compress them, and upload them via dial-up modem to its upstream BBS. That BBS would decompress the incoming messages, distribute those messages that were destined for its users, add its outgoing messages to those it just received, compress all outgoing messages, and dial its upstream BBS so that it could upload its bundle of outgoing messages. This was all via automated dial-up connections, which were mostly attempted overnight. It was funky, but it worked.
Thanks to FidoNet, users of any FidoNet-connected BBS could exchange email with users of all other FidoNet-connected BBSs. Eventually someone created a gateway to the Internet.
One reason for FidoNet mail’s success is that it separated the message transport function from the user agent function. Users of CBBS systems could easily exchange messages with users of Searchlight BBS systems, across the globe. All FidoNet user agents allowed reading and replying to email while offline.
I used a FidoNet-based email frontend and backend called D’Bridge, which was written in Borland’s Turbo Pascal by Chris Irwin. It was very slick, but I never saw it progress beyond the “work in progress” stage. D’Bridge allowed my PC to become a FidoNet node or point, so I could correspond with FidoNet BBS email users around the world for the cost of a local phone call. Email reading and replying was done off-line, so phone costs remained low. (I met Chris — a bungee jumper and skydiver — once in Miami. He told me that he’d bicycled to the South Miami post office to mail disks of his program and on his way home, his bike was stolen out from under him — as he was riding it! Miami was frantic in the 1980s.)
Eventually AT&T introduced its AT&T Mail service. It was a warmed-over Unix-based mail system that was rushed to market when AT&T’s long-delayed packet-switched network failed to appear. It offered a uucp gateway and services similar to MCI Mail, but I preferred MCI Mail’s much friendlier user interface.
Western Union EasyLink
Western Union introduced its EasyLink service as a competitor to MCI Mail. It had an unfriendly user interface and a directory that was difficult to search, but offered gateways to most other public email systems. Around 1991, AT&T relabeled EasyLink as AT&T EasyLink. It remained clunky and expensive.
A major problem with most public email services was that users were billed by the minute while their modem remained connected.
About 1986, I installed Action Technologies’ MHS (Message Handling Service), a Novell Netware server based mail handling system with an open application programming interface. Action Technologies’ own Coordinator email client was intriguing, but too structured for most users. In 1988 we settled on Davinci eMAIL, a client-based system which used MHS for message transport between mail hosts. It stored a user’s messages in either a private local database or a shared database on a server. DaVinci eMAIL served us well for many years, first in text versions and later in Windows versions.
A number of commercial and shareware gateways for MHS appeared. We eventually had MHS gateways to MCI Mail, AT&T Mail, fax, uucp, and SMTP. For some reason, Novell was slow to update MHS, which left an opening. A small Maryland based company named Infinite Technologies produced an MHS compatible “post office” with a feature superset. It was called Connect2. We replaced all MHS hosts with Connect2.
Sidenote: Infinite Technologies’ founders were Brett Warthen (a prolific coder) and John Madill. John was one of the founders of FidoNet. Small World. At least then it was.
MHS (and Connect2) connected organizations by transporting messages between disparate systems primarily using dial-up connections, but as the 1990s drew to a close, that role was acquired by products that employed SMTP (Simple Message Transport Protocol) on the public Internet.
About 1997, my employer’s new owner mandated deployment of Lotus Notes. It was essentially a shared database with a quirky email-like user interface. Most users preferred the intuitive DaVinci eMAIL user interface.
In 1996 Microsoft introduced its first release of Exchange. It offered X.400 compatibility but no compatibility with MHS. I didn’t think that it had a future. I was wrong.
I use a variety of email systems. On my Android phone, I use the friendly email program that’s bundled with Android 4.2.2. On PCs, I use Mozilla’s Thunderbird or Microsoft’s old Outlook Express. I avoid Microsoft Outlook; I just don’t like its user interface. Occasionally I use Microsoft Office 365’s Webmail, with its horrible user interface.
At one time, computers attracted loners. The first time I sat a terminal, I felt at home. Not with other people. With the machine. Its layers of mystery intoxicated me. It also satisfied a desire for control: the machine would do exactly what I told it to do, including stupid things. The machine was mindless, a blank slate. I could transfer my ideas to it. All that I needed to do was learn its language. I began with BASIC and eventually learned assembler. Its small vocabulary and strict syntax presented a challenge.
Years earlier, when I read Inside The Third Reich, Albert Speer described the thrill that he felt when, after 10 years of imprisonment, he was allowed to operate an electric floor polisher. He said that the feeling of power when he switched on the polisher convinced him that he’d not been cured. I know what he meant.
Today, computers attract people who wish to socialize via Facebook, Google+, Pinterest, forums, etc. The computer as a machine is becoming invisible.
Why? Giant strides in data communication and processing power. Most consumers today buy computers to communicate, not to compute. Maybe we shouldn’t call them “computers” and instead call them “communicators”.
Edward Snowden’s leak of NSA documents has divided journalists into two camps:
The Guardian‘s Glenn Greenwald tore into “actors who play journalists on TV” during his speech from Hong Kong last week. Greenwald calls CNN’s White House reporter “the White House spokesperson”. I agree with Mr. Greenwald: it’s the role of the press to uncover illegal, unethical, and immoral behavior by individuals and institutions — all institutions.
This affair has revealed journalistic and political corruption and has, for many liberals, knocked Mr. Obama from his pedestal.
You may assume that one or more three-letter federal agency records every instance of your electronic communications. Why? Because they’re inhaling all packets that enter and leave major carriers’ switching centers. Read Paranoid? Worry about Comcast and AT&T, not Google.
I’m convinced that every tech company contains a handful of engineers and technicians who know their product; every other employee helps create layers that prevent customers from speaking with them. AT&T is no different. I have a couple Miami-based clients who were unable to see their own websites (hosted in Orlando) when using their AT&T DSL Internet connections. Their traceroute results revealed that their packets were being dropped by AT&T, rather than being routed to Level3. Their packets never left AT&T’s network.
Twice I contacted AT&T’s DSL support department without success. One support person suggested that AT&T’s DNS servers may not have received the update for the clients’ domains. I was certain that this wasn’t the case, but obediently followed her instructions on how to request a DNS update via email, with no result. The other support person suggested that the problem wasn’t AT&T’s. On a theory that maybe Level3 was rejecting the packets, I posted a request for help on a Level3 tech support page and received no reply.
I called again. John Ledyard, another AT&T DSL support person, listened, agreed that the problem could be in AT&T’s routing tables, and asked me to email him the source and destination IP addresses together with a broken traceroute result. Mr. Ledyard told me that although he couldn’t personally fix the problem, he would forward my email to someone who could fix it. Voilà! Within a week, the packets were reaching the destination host.
I don’t know exactly what was broken or why the problem occurred, but now it’s repaired. All’s well that ends well.
President Obama has nominated Tom Wheeler, another in a long line of political hacks at the FCC, for the FCC chair. This choice receives mixed reviews from observers: Obama’s new FCC chairman isn’t a reflexive shill for carriers, but he’s still a bad pick. His close ties to the cable TV and mobile phone industries worry me. Wheeler is former head of the National Cable and Telecommunications Association and the mobile wireless trade group CTIA (Cellular Telecommunications Industry Association). Translation: he lobbied for these industries. He’s also a major Obama campaign fund raiser. (His predecessor, Julius Genachowski, was an Obama election campaign committee official.) Nothing new here — it merely continues a long tradition of patronage at the FCC.
Remember Obama’s “no lobbyists in my administration” pledge?
In my opinion, Mr. Wheeler is way too closely connected to industries that fall under the FCC’s oversight. You can bet that his cable TV and cellular provider buddies hope that Congress approves his nomination as FCC Chairman. It’s ironic that the two segments of the American electronic communications market that are infamous for gouging the consumer are the industries for which he’s been a champion. If he runs the FCC, don’t expect change in either of these cozy shared marketplaces. Both industries are fat and happy, with limited competition. In fact, expect legislation to prevent municipalities and Google Fiber et al from competing with the incumbents.
Now, more than ever, the FCC Chairman should be independent of industry associations. Tim Wu, respected telecommunications observer, writing in The New Yorker, described The Coming War Over Net Neutrality. uncoveror comments,
The FCC, by getting in bed with the industries it is supposed to regulate, has undermined its very reason to exist. They are a corrupt agency for sale to the highest bidder.
I hope that Wheeler’s appointment is bounced by Congress and Mr. Obama instead nominates Susan Crawford, who doesn’t seem to be in any industry’s pocket. I almost forgot: she didn’t raise election funds for Mr. Obama. Hey, I can dream, can’t I?
Video clip: former FCC board member Nicholas Johnson calls Wheeler’s nomination “somewhere between bizarre and outrageous”.
While listening to podcasts, I came upon Susan Crawford’s argument that in the United States, access to the Internet has been managed to benefit large corporations, and not for the benefit of the public. She points out that retail communication costs are rising in the United States, while they’re falling in most other countries. Why? Lack of competition. She recently appeared on Bill Moyers’ PBS TV show with Susan Crawford. She’s studied and documented the parceling of the American broadband market by the usual suspects: AT&T, Verizon, Comcast, Time-Warner, et al.
Both the telephony and cable-TV industries require very large capital investments, so the entry fee is high, effectively keeping newcomers out of their markets. Ms. Crawford has discovered that the incumbent cable-TV and telephone companies have consolidated and co-operated so that each broadband vendor enjoys a monopoly or at worst a shared monopoly.
Despite plummeting computing and data transport costs, average monthly AT&T bills have risen(!). This makes no sense. One reason for this absurdity? Itemized bills with numerous indecipherable items; the amount of each creeps upward imperceptibly a few times each year. Another reason: bloated management filled with MBAs, lawyers, and “managers” who don’t know Ohm’s Law. It’s surprising that this gouging has taken place under the watchful eyes of fifty state Public Utilities Commissions and the Federal Communications Commission. Mr. Johnston explains that the common carriers’ lobbyists have helped shape regulations to favor the regulated companies.
Use Traceroute to identify which enroute router fails to route your UDP packets to the destination host. Often the culprit is a firewall or a mis-configured border router. Traceroute for Android completes my little bare-bones toolbox for troubleshooting Android IP communication problems.
What about my iPhone? Nice Trace, available from iTunes, seems to display traceroute data for the iPhone. I’ve not tried it.
Do you need to make low-cost international calls from your mobile phone? The new Skype To Go service may do the trick. Set up a Skype To Go account and forward calls from your normal number to your new Skype To Go number.
Use any phone (that you authorize) to call a dedicated local number and Skype routes your call via Skype’s VoIP-like protocol over the Internet to the international destination phone. Caveat: Skype To Go is in beta test and is available in only a limited number of countries.
Do you want to be easily reached by phone while you’re abroad? While abroad, purchase a local mobile phone for temporary use, and use Skype To Go to forward calls that are received by your normal phone number to your new temporary overseas mobile phone. Voilà! No international roaming charge. Caveat 2:
If anyone calls one of your Skype To Go numbers from a phone you haven’t registered on your account, an automated operator will ask them to enter one of your registered phone numbers along with your PIN.
On Monday, the United Nations’ ITU (International Telecommunications Union) will convene its twelfth World Conference on International Telecommunications (WCIT-12) in Dubai. Its last full meeting was in 1988. The meeting runs from 3 through 14 December. Government telecom administration representatives from 193 nations will attend. The ITU has traditionally concerned itself with telephone and radio spectrum allocation; now some governments wish to use the ITU to censor Internet communication. The U.S., like all 193 member nations, has only one vote on each proposal.
For decades these meetings went unnoticed by the general public, so nobody cared that meetings were closed and meeting documents weren’t available to the public. Now, some WCIT-12 documents appear on wcitleaks.org. Its News page contains links to fascinating articles that discuss the contentious issues posed by the growth of the Internet within repressive nations.
One item on the agenda is the demand that anonymity on the Internet be eliminated. Another would endorse Syria’s closing of access to the Internet. Dicatorships and kleptocracies fear the free exchange of information.
It appears that WCIT-12’s theme may be an attempt by nations with sketchy human rights records to wrest control of the Internet from its US-based roots. ICANN (Internet Corporation for Assigned Names and Numbers — it oversees domain names and IP addresses) is in their sights: Latest WCIT Leak Makes Explicit Russian Desire to Overturn ICANN:
According to the proposal, “Member States shall have the sovereign right to manage the Internet within their national territory, as well as to manage national Internet domain names.” And a second revision, also aimed straight at the heart of today’s multi-stakeholder process, reads: “Member States shall have equal rights in the international allocation of Internet addressing and identification resources.”
Dozens of proposals secretly circulating ahead of the WCIT meeting would go well beyond usurping ICANN’s authority, and would if adopted introduce sweeping architectural changes that would allow the ITU and its members to redesign the Internet to something much more controllable.
Maybe T-Mobile is exempt from truth in advertising laws. Maybe they’ve quit speaking English and converted to Newspeak. I wonder because T-Mobile’s “Unlimited Plus” data plan is not unlimited. For the first 2 gigabytes he receives each month, the subscriber can access the Internet at 4G speed (about 3 Mbps measured download speed); then the connection speed drops to about 50 kbps. It’s throttled. It’s capped. It’s pathetic. It’s not unlimited.
This is another case in which our bloated government has failed its citizens. Doesn’t this false advertising violate an FCC rule? Where’s the The Federal Trade Commission (FTC), whose “principal mission is the promotion of consumer protection and the elimination and prevention of anti-competitive business practices”? Answer: asleep at the switch.
My Android phone occasionally disconnects itself from the Internet, especially after re-starts. I check connectivity using this procedure. The disconnection cause? For some reason, on my Samsung Insight phone the “Use packet data” checkbox randomly unchecks itself. To reconnect, I go to Home, Settings, Wireless and network, Mobile networks. Make sure that “Use packet data” is checked. Test again.
If no connection, choose “Network operators” under “Access point names”, then choose “Search now”. Make certain that your carrier’s name appears; you may be out of range of a cell site. Another possibility is that your phone may have forgotten who your cellular provider is; correct this within “Network operators”.
If you still can’t connect to the Internet, contact your cellular provider.
Update, December 2015: My Samsung Galaxy Light SGH-T399 phone with Android 4.2.2 is slightly different than my older Android 2 phone. At the top of this article, I added a large screenshot from it. I got to this screen by tapping
I planned to listen to two NYC-based podcasts for tech geeks tonight, but their server was unreachable. Then it dawned on me: their server is located in lower Manhattan. Powerless lower Manhattan, thanks to the flooding caused by hurricane Sandy.