Does anyone here use the new Clearwire WiMax Internet service -- the fast, inexpensive, simple internet service available in a few cities? I understand that they block Ports 25, Port 80, file sharing ports, and perhaps streaming video and audio! WTF? If so, what's the point of their Internet "service?" Anything from anyone? I was going to switch, but not any more.
I don't understand why they would block ports 25 and 80, but I don't blame them even a little bit for blocking file sharing ports. I hate it when some d*****ad is so busy stealing copyrighted material (yes, yes, I know it's not all copyrighted material, maybe only 99.9%) that he clogs up the whole network for everybody. As for streaming audio and video, it can be as bad a problem as file sharing, but not usually. Clearstream has to buy their bandwidth from their competitors, normally the big telcos. It isn't cheap for this bandwidth and letting someone hog an inordinate amount compared to what they're paying per month doesn't make business sense.
Clearwire is also allegedly blocking VoIP from Vonage to favour their own VoIP service:
's too soon for Clearwire to respond to the accusation.
Outgoing port 25 blocking is very common for broadband providers. However, any others are rather unusual. Got any specific port numbers or services that don't work with Clearwire? Outgoing or Incoming?
I agree with your comments about file sharing ports. And with a bit of research I "think" port 80 handles web hosting and port 25 may only handle SMTP mail servers, both of which I won't use. But the streaming thing is serious to me -- I like to stream news reports from places like Foxnews and MSNBC. In any case, thanks for the reply. Also note that I'm talking about Clearwire, not Clearstream. Regards..........
"EW" wrote in news: firstname.lastname@example.org:
Wow....first time I've EVER seen Clearwire mentioned here.
I am a former employee of the 'startup' Clearwire, before it was purchased. Originally the business plan was to provide service for commercial customers.
If indeed they do block port's 80 and 25, I would assume it's incoming connections that are blocked, so you don't run an SMTP server or web server from your home. Most broadband connections forbid this in the customer-agreement anyway.
File-sharing totally kills bandwidth, wired or wireless.
My question is really, how well does it work? CW designed and deployed their own proprietary equipment in the networks before the purchase. The original OEM equipment was 2.4 ghz, a bit slow, but the design offered a
25 mile link distance, at full bandwidth with no speed degradation. Also, the OEM stuff was not just a wireless bridge but an actual router. With residential wireless, the biggest issue with subscriber's is having a big ugly antenna at their location. With the buyout, and a switch to the current hardware, that requirement was supposed to be minimized and most are supposedly able to use this small little box with it's own antenna. I'm just wondering how well it works.
I'm not a Clearwire customer or employee, but think I can guess how it works. Blocking incoming ports (to the customer) does not require anything at the customer end. It's done by the central router which is probably some very big Cisco or equivalent monster router. All it needs to do is look at the incoming ethernet packets, inspect the destination port number (i.e. 80) and just drop the packet. Nothing on port 80 ever gets transmitted or arrives at the customers.
Dealing with outgoing port 25 blocking is a bit more difficult. One could easily have the big central router do all the work in the same way. However, that means that the packets destined to port 25 will be transmitted by the client radio before getting dropped by the central router. That's a waste of precious airtime. If the CPE (customer premisis equipment) really does have a built in router, then outgoing port 25 packets are best dropped at the source. The mechanism is the same. The router inspects the destination port number and drops anything on port 25. I can't tell from here which way outgoing port blocking is implemented. It might also be both at the central router and the CPE router. If there's no CPE router, then it all has to be done at the central router.
What I find interesting is that Clearwire is apparently also blocking ports used by Vonage VoIP SIP phones. Since Clearwire is not a common carrier, there's no legal restriction preventing this practice. However, in my never humble political opinion, they're just asking to get legislated into the ground in the upcoming revision to the Telecom Act which will include VoIP guidelines. It also begs the question of "what's next?" Are they going to filter VPN's, streaming video, file sharing, and competitors web sites? Maybe they won't absolutely block services, but simply slow them down? These have been tried by other ISP's with universally dismal results.
Jeff, thank you, and all the others who provided lots of good info. I get the stuff about the blocked ports (finally) but one final question please. In your apparently knowledgable opinion, how would Clearwire, or anyone, slow or block streaming media without totally restricting the customer's bandwidth? This wouldn't be a port limitation, so......... how?
Bottom line, I guess I'll just stay with my "overpriced" broadband fixed-wireless provider who limits absolutely nothing!
Bandwidth Management and traffic shaping are the buzzwords. There are several methods. The best of the bunch is to delay the ACK TCP packet. The IP stack thinks it is talking to a slow dialup modem when the ACK's are delayed, and therefore slows down sending packets. It can also be done by simply dropping packets thus forcing a retransmission. However, that's gross, disgusting, and inefficient. There are also various methods of QoS (Quality of Service) and MPLS (Multi Protocol Label Switching) which are basically nice terms for giving priority to time sensitive packets (i.e. VoIP) while delaying other packets (web and email).
Here's more from those that sell the boxes:
are lots of boxes that do bandwidth management (as well as security and virus blocking).
I use (and abuse) a simple floppy based FreeBSD based program that wasn't exactly designed for the purpose, but works well enough.
's also handy for simulating IP traffic congestion, anomalies, and abominations.
Just to clarify this, you must distinguish between "ack delay" and TCP window shaping. Ack delay doesn't do much more than delaying the original data in a queue, because an ACK can't be sent until the data is actually received. Window shaping can actually get the sender to send less data; the result is reduced traffic on your network, which reduces queue depth and smooths the flow of your entire network. The lower end "queue management" devices, such as dummynet, cisco and the stuff in linux, does not improve things for "other", non-managed traffic on your network. What is often seen when using those products is a perceived improvement in traffic for managed types, while screwing up everything else on the network. The reason is that queuing methods merely shift the latencies from one type of traffic to another, while true window shaping can actually reduce latencies for all traffic.