Vonage recommends letting its box sit between the Internet and my computer, so that its traffic always gets priority. However, there’s no way I’m going to give Vonage control of Internet connection, so I have it plugged into my network, routing traffic through my Fedora box.

Unfortunately, this means that when something is generating a lot of outbound traffic, there isn’t enough outbound bandwidth for Vonage, so call quality is extremely poor.

With Linux Advanced Routing & Traffic Control (LARTC), it is possible to configure Linux to prioritize Vonage (or any other preferred application) higher than other outbound traffic. There’s lots of information on the Web about how to configure LARTC, but I found that most of it is either too dense and detailed or not detailed enough, and I couldn’t find any plug-and-play LARTC configuration tool for Fedora (it’s somewhat puzzling why such a thing hasn’t yet been written, given how long LARTC has been around for). With a little work, however, I managed to figure out how to do it. For the benefit of the others, I’m spelling it out step-by-step here with a level of detail I was unable to find elsewhere.

Shaping Vonage traffic

1. Download Wonder Shaper and read the README file in it.
2. Now download my tweaked version of the “wshaper.htb” script that’s included in the Wonder Shaper distribution. The most important change in my tweaked version is to add a “real-time” traffic class and put Vonage in that class, so Vonage is prioritized even higher than interactive traffic like SSH.
3. Copy my version of the script that you downloaded into “/etc/init.d/wshaper”, making sure that it is executable.
4. Edit the “DOWNLINK”, “UPLINK”, and “DEV” settings at the top of the script. Note that the first two sittings are in kilobits per second, not kilobytes, and that the values you put here should probably be about 90% of the nominal speeds of your Internet connection. You can use a higher percentage if you find that you aren’t using all of your bandwidth when doing network-intensive operations — you might have to do some trial and error to get it right. Don’t forget to update these if you switch to a faster or slower Internet connection!
5. Run “/sbin/chkconfig wshaper on“.
6. Run “/sbin/service wshaper start“.

That’s it!

A note about how Vonage traffic is matched

This is the code in my version of wshaper that matches Vonage traffic:

tc filter add dev $DEV parent 1:0 protocol ip prio 10 u32 \
        match ip tos 0xb8 0xff flowid 1:10

The secret to what makes this work is the “match ip tos 0xb8″ which I’ve shown in bold. “TOS” stands for “Terms Of Service”, which basically means, “The section in the packet header which indicates what level of service the packet should be given.” I figured out the correct TOS value to match against by doing the following:

1. Use wireshark to capture packets on the interface of your Internet connection or the interface of the local network your Vonage box is plugged into.
2. Make a Vonage phone call while wireshark is capturing.
3. Find a packet in the capture with protocol “RTP” and source IP corresponding to your IP address (if you’re capturing your Internet traffic) or the IP address of your Vonage box (if you’re capturing your local network).
4. Expand the “Internet Protocol” subtree of the packet analysis and note the value following “Differentiated Services Field:”. That is the TOS value you should match against in your LARTC configuration.

Other traffic shaping

Here are some examples of other traffic shaping you can do with Wonder Shaper. If you’d like help figuring out how to make other kinds of traffic not mentioned here either high-priority or low-priority, feel free to post a comment and I’ll try to help.

Amazon S3 and other recurring large uploads

I back up my system on a daily basis to a ReiserFS filesystem stored on Amazon S3, using the wonderful package s3backer. For ten cents per gigabyte per month plus minimal upload costs, I get highly available, redundant storage of my critical data. It took a little tweaking to make this configuration stable enough for my tastes (when I get a chance I’ll post the details about that separately), but now that I’ve got it set up, I’m pretty happy with it.

The one thing I’m not happy about is that while the backup is running, it consumes a huge amount of bandwidth, and interactive performance for everything else suffers. I don’t want a Web page to take ten seconds to load just because I’m running a backup! Wonder Shaper can help with this problem:

1. Note that files are uploaded to Amazon S3 at the host s3.amazonaws.com.
2. Run “host s3.amazonaws.com” to get its IP address.
3. Run “whois ip-address” to look up the whois information for the IP address.
4. Find the “CIDR” line in the whois output, e.g., “72.21.192.0/19″.
5. Add the CIDR value to the “NOPRIOHOSTDST” line at the top of the “wshaper” script (if you have multiple destinations on this line, put them all in quotes separated by spaces, and make sure there’s no space before or after the “=” sign).
6. Run “/etc/init.d/wshaper” to reload the new configuration.

One caveat I’ll note is that the network block for Amazon S3 may change from time to time, so if you start to notice network performance suffering while a backup is running, repeat the steps above to find out if there’s a new network block you need to add to the prior ones in NOPRIOHOSTDST.

You can use this for any service to which you do large data uploads on a recurring basis.

You can configure Vonage to email you about voicemail messages.  The email contains the actual voicemail message as an audio attachment, but what it doesn’t have, inexplicably, is the name of the caller pulled from caller ID.  This has annoyed me ever since we switched to Vonage, and I recently finally got annoyed enough to finally do something about it.  I’m posting my solution here on the off chance that it’ll be useful to others.

To take advantage of this hack, you have to have the ability to filter the contents of your incoming email, e.g., with procmail.  If you don’t know what that means, then you should probably stop reading now. :-/

My solution consists of two scripts and two configuration changes.  First, the scripts:

1. The script vmail-cid.pl fetches the caller ID information for recent calls from www.vonage.com and saves it in a CSV file.
2. The script vonage-vmail-filter.pl reads the aforementioned caller ID CSV file, as well as a CSV file you’ve exported from your Outlook contacts, and uses the information in those files to filter a voicemail notification email message on stdin and send the (possibly modified) notification to stdout.  You can configure the script which of the two CSV files to read, i.e., you can take advantage of either the caller ID information from vmail-cid.pl, or the Outlook export CSV, or both.

Now, the configuration changes:

1. You need to set up a scheduled task, cron job, or whatever to run vmail-cid.pl periodically to keep the caller ID CSV file up-to-date.
2. You need to tie vonage-vmail-filter.pl into your email delivery, e.g., by editing your .procmailrc file (for which there is an example in a comment at the top of the script), sieve configuration, or whatever.

When all of this is done properly, then every voicemail notification you receive will be updated with the caller ID or Outlook Contacts name for the calling phone number, if it’s available, before it lands in your mailbox.

Click here to download a zip file containing the scripts.  See the comments at the top of the scripts for additional details.  As always, please feel free to send me any questions, comments and suggestions you might have.

Enjoy!

I got them to lower it to $75 per month, but I had to pay extra for all non-local and long-distance calls.  That was still too much.

They raised the equipment charge for my cable modem from $3 to $5 per month.  That pissed me off, so I bought my own cable modem.

Not only that, but I decided it was time to send Comcast a message for being so slimy, so I switched to Vonage for phone service for $25 per month.  You would think that would have lowered my total cost, except that when I canceled my Comcast phone service, I was no longer eligible for the special “bundle” rate on internet service, so they jacked up my internet service to $60 per month.

That pissed me off even more, so when I called today to swap out Comcast’s cable modem for my own, I also told them to downgrade me to their $40 per month internet service.

Believe it or not, what you get for that ridiculously high price is a 1mbps internet connection.  Yes, you read that right, one megabit.

Fortunately, Comcast isn’t the only game in town.  RCN will sell me a 1.5mbps connection, 50% faster than Comcast’s, for $25 per month, i.e., 37% less.  That’s not even a promotional rate.  Or, if I feel like spending $5 more per month, I can get a 10mbps connection, i.e., ten times as fast as Comcast for 25% less.  And although that is a promotional rate, unlike Comcast, RCN will let me sign up for any new promotion that becomes available after my 12-month contract is up.  Heck, even Verizon charges only $20 per month, half of what Comcast charges, for a 1mbps DSL line!

I haven’t switched to RCN yet, but I’ll probably be doing it some day soon when I’m in just the right mood.

Below is the letter I just sent the CEO of Comcast explaining how they managed to lose an $80 per month revenue stream over a lousy $2 per month.

P.S. If you decide Vonage is right for you too, email me and I’ll send you a referral, and we’ll both get a free month of service!