vonage causing denial of service attack?

Posts: 28 · Vonage Forum Junior Joined: Jul 10, 2004 Posts: 28

I sent this trouble ticket to vonage this morning. Anyone else experienced the following?

"Description of Problem:
At the moment the Vonage adpter box is not connected to the network. The adapter is in a bag in the car. Never the less when someone dials my vonage number and I answer with my cellphone, which is set to simultaneous ring, the local network disconnects from the internet and client computers, connected via wifi, lose their connection to the local netowork until the call is disconnected. This behavior happened several times. We tested this behavior 3-4 times this morning with the same result.

"It appears Vonage servers are contacting the last known IP of the Vonage adapter and creating a denial of service attack that goes on until the vonage servers see the call has been disconnected.

"Vonage servers shouldn't be trying to contact a device that is not logged on to it's servers already and even that shouldn't cause a denial of service. Please advise."

Posts: 429 · Posted: Fri Jun 22, 2007 1:00 pm Post subject:

Quote:

the local network disconnects from the internet and client computers, connected via wifi

Are you sure this isn't an RF issue with your phone and wifi network? Even if Vonage was hitting your last-known IP address (which I cannot in my wildest imagination believe, because VoIP does NOT work that way)-- and furthermore we'd have to assume they did it with such voracity as to cause a DoS attack on your external WAN connection, again almost totally improbable-- it would still not affect your LAN. It would only affect your internet connectivity.

I do believe you have another issue, probably related to RF from the cellphone knocking down your wifi.

Posts: 327 · Vonage Forum Evangelist Joined: Dec 13, 2005 Posts: 327

If you have a bluetooth headset on the cell phone, try running without it and see what happens to your WiFi. WiFi and Bluetooth operate in the same band and often look like "noise" to each other. You can verify that Vonage is doing nothing to you by calling and if you go directly to voice mail o off to another number, then they know that nothing is registered.

On soft phone accounts, if the thing does not register every minute, Vonage servers assume you're gone. I expect the standard accounts are the same, though I can't see that information anywhere.

Posts: 414 · Posted: Fri Jun 22, 2007 2:05 pm Post subject:

howiewifi wrote:

On soft phone accounts, if the thing does not register every minute, Vonage servers assume you're gone. I expect the standard accounts are the same, though I can't see that information anywhere.

The standard routers have a keep-alive registration every 20 seconds, with a full re-authentication every 4 hours or after loss of connectivity. So, theoretically all it takes is 20 seconds for Vonage to know you are no longer there. As stated already, VoIP does not just send packets to the last known IP address it has on file, that is not the way VoIP works at all. Even if they were sending traffic to your IP, it would be the same as a standard call coming in and would not cause your internet connection to drop out or be anywhere near a DDoS attack, nor would it effect your LAN. Furthermore, when a call is forwarded to any other phone, the data for the call is no longer going through your Vonage router at all. It is simply a connection between the Vonage server and the phone you forwarded the call to. In closing, this is not an issue with Vonage at all. It is a conflict between your cellphone and what appears to be your wireless router.

Posts: 28 · Vonage Forum Junior Joined: Jul 10, 2004 Posts: 28

More trouble shooting found a more harmless problem. I changed the channel of the wifi ap's from 6 to 1. That created interference with cordless phones in the location. The problems appears to be solved by moving the wifi channell from 1 to 10 and adjusting channel choices on the phones. The phones weren't suspects in the beginning because they'd worked flawlessly with wifi for years.

Moral of the story, avoid running 2.4 Ghz phones in a house with wifi. It will work but if channels get changed around there could be interference that's not considered because they were not a source of trouble in the past.