March 14th, 2006
"Voice Over IP (VOIP): Can You Hear It Now?"

Minutes of the 3-14-06 meeting of the Rocky Mountain Internet Users Group (RMIUG):
"Voice over IP (VOIP): Can You Hear It Now?"


Microstaff (www.microstaff.com) provides refreshments

Copy Diva (www.copydiva.com) provides the audio-visual equipment

NCAR (www.ncar.ucar.edu) provides the facility

ONEWARE (www.ONEWARE.com) sponsors these minutes.





RMIUG meetings occur on the 2nd Tuesdays of odd-numbered months. Email Josh Zapin with topic and speaker ideas.
May 9: Google, the New Big Brother.
July 11: SIG-CHI (computer-human interactions)
September 12: TBD
November 14: The Cluetrain Manifesto Revisited



- SandCherry (www.sandcherry.com) in Boulder is hiring various positions.

- Labor available:
Charles La Motta, Oracle Developer Babu Bangaru, Software/Test Engineer



Voice Over IP, a method of transmitting your voice calls over the same Internet lines that carry your email, is exploding. In a speech given by former Federal Communications Chairman Michael Powell in 2004, he rattled off the following statistics:? - 2 percent of US firms use some form of IP telephony, and this number is expected to grow to 19 percent by 2007? - 73 percent of wire line service providers and 31 percent of wireless operators either have implemented, or are testing packet telephony in their networks? - 50 percent of Internet households are interested in Internet Voice as a way of reducing monthly long-distance charges

And that was almost 2 years ago!

Why is there so much change? Because if you already have a broadband Internet connection (and Neilsen/NetRatings says that over 60% of us do), then you can save lots of money on your phone bills. Consumer Reports, a leading independent consumer publication, found that nearly 80% of the people who made the switch to VoIP saved at least $20 per month, with 34% saving $40 or more!

Not to mention that you could also give your local Bell the boot! (That is if you don't have broadband through them - in that case, it would be just part of a boot.)

In addition to using our exiting broadband pipe to cut our bills, people are switching to gain mobility, features, and cheap international calling.



Eric Laughlin is the founder of Voipreview.org, a website that helps people chose VoIP plans. Eric is a serial Internet entrepreneur and has appeared on Tom Martino's Troubleshooter and has been quoted by The News Observer in Raleigh, NC in "Voice Over Internet Has People Talking," by the New York Daily News in "Dialing Up Phone Calls on Internet," and in the Boulder County Business Report.

June Hu joined IBM Network Service Division in 1998 as an IT Specialist, after earning a master's degree from CU Boulder in 1997. For almost eight years she has been one of the key persons in the maintenance of IBM Boulder's internal network. June is now responsible for the VoIP project at the IBM Boulder site, getting one of the largest information companies in the world VoIP-enabled.

Speaker slide presentations are available here.




VoipReview.org was the first Voice Over Internet Protocol search engine, detailing lots of calling plans and providing side-by-side plan comparisons.

VoIP is simple and easy to use, routing your phone calls through your existing high-speed connection. It even works on dialup connections.

VoIP has totally changed the paradigm for wireline services: you now have a thousand companies to choose from, as you can literally pick any phone company in the world. You can even have a phone number in Korea and have it ring here, with no long distance charges.

Analysts predict 18 million subscribers by 2010, with $4 billion in revenue. Currently there are only 4.5 million subscribers, which is about five percent of the market. VoIP provider Vonage was the biggest advertiser on the internet in 2005.

- Phone Line Replacement (independents/telcos(like Qwest) & cable companies (not mobile).
- IM-Based (like Skype)
- Hybrid (cell phone+WiFi VoIP)--still a few years away

- Price: VoIP provides huge savings, charging pennies instead of dollars for local, long distance, and international calling.
- Free calling features: You get standard features plus others like click-to-call, voicemail-to-email, real-time billing, conferencing, etc.
- Convenience: Features like click-to-call are good for small business.
- Mobility: Your VoIP device works with any internet connection.

- Power outages will shut you down, unlike standard phone service.
- 911 calls won't automatically broadcast your location.
- High load on your internet connection can affect performance, causing call failure.
- IM-based VoIP (Skype) doesn't allow number portability, 911, or use of a regular phone.

Overall, the disadvantages are pretty minor.

Think about how you make and receive calls, how much time you spend on the phone, where you call, what features you need, and what uptime reliability you need. Generally, reliability is quite good (although not nearly up to the very high standards of traditional wire lines).




VoIP is important in the corporate, big business environment.

Components include an IP Network (talk on your computer using data traffic) and a traditional PSTN/POTS (talk on your regular phone using voice

PSTN: Public Switched Telephone Network, aka POTS:
Plain Old Telephone Service

When voice is enabled on IP network, a codec converts
voice into IP data.

Pick up a handset, dial a number, number received at
Cisco Call Control Manager (CCM) cluster, server converts phone number to IP address of recipient, and rings the recipient's phone.

To call a regular phone, the CCM server will forward information to the Voice Gateway that transfers the phone number to the regular PSTN phone network.

The three things you need to set up VoIP in a business are an IP Phone, a CCM cluster, and a Voice Gateway.

Converts voice to IP data. The phone generally has enough built-in standard ports so you can connect it to your network without installing any other ports or switches.

A software-based call-processing component, including publishers, subscribers, and TFTP servers.

Converts analog voice signals to and from IP telephony packets. It has T1 and Ethernet ports to make its connections. There are many scalable solutions out there from Cisco, Avaya, and Semion.

VoIP allows Toll Bypass (aka least cost routing): This is using IP Intranets to route your call instead of traditional PSTN. It's good if you have lots of office branches. The Voice Gateway talks to proxy servers to notify the remote Voice Gateway, and this saves you lots of money because you've cut out the regular phone network entirely. Sometimes you can use some of your existing PSTN infrastructure to support Toll Bypass.

- Cost savings (+ using combined infrastructures)
- Flexibility: mobility, conferencing
- High Performance: including video conferencing

Delay: Latency delays can be nasty with voice.
Jitter: Arrival times can cause noise.
Lost Packets: VoIP uses the UDP transportation protocol that doesn't retransmit lost packets (if you retransmit, it confuses the voice flow)

Quality of Service (QOS) we implement to deal with the
We classify traffic into different categories. Voice data goes in the time-sensitive category. Each category has a value to identify importance. Then we create a policy map to help the system respond to category values and route traffic appropriately. The policy criteria also depends on the source address (user making the call), the protocol type of the packet, the packet's application port, and the destination address (user receiving the call).

We use G-series codecs to convert analog waveforms into digital signals.
G.711 (PCM) is best: 8000 samples per second, a 64kbps signal.
G.726 (ADPCM) uses a 4-bit code to make a 32kbps signal.
G.729 (CS-ACELP) only needs 8 kbps, so it doesn't provide as good voice quality.

A LAN with G.711 gives you the best voice quality. A WAN with G.729 can be useful for bandwidth savings.

H.323: Widely supported and strictly defined, used in converged networks.
SIP: Less strictly defined, but easier to support. Gaining in popularity.
MGCP: A plain-text protocol to control gateways.

A real time protocol for voice transfer. Packet includes MAC header, IP Header, UTP header, and RTP message.

VoIP is strong and reliable, although there are typically some T1 problems and code bugs to work out as you are setting things up.


Q & A

NOTE: David James, a VoIP Architect with IBM, joined June and Eric for the panel discussion.

Q: For home users with Comcast cable, for example, there is no QOS from Comcast so performance simply depends on traffic. Since Comcast is in the phone business, couldn't they do reverse QOS on VoIP users to stifle competition?

Eric: Your performance will vary depending on traffic, and yes, theoretically a company could do reverse QOS if they wanted.

David: You can do some QOS at your end to prioritize your data packets. Often the basic VoIP devices can do this for you. But after that you are at the mercy of the ISP once your information leaves your network.

Q: How mass-market friendly is VoIP? VoIP seems to move complex call management from the phone company into your home. Will it only take off with technically savvy people?

Eric: I think everything will eventually be VoIP. Management is becoming faster and easier.

David: Cell phones used to be awful, but now we all have them because customer demand drives the business. I think big companies will be dropping their regular land lines. There are ways to overcome the technical challenges and make it easy for people.

Q: How is VoIP architected at IBM?

David: we are a Cisco shop, with some Avaya and Semion in some locations. We have a bypass network, a WAN provider for a lot of bandwidth used primarily for Toll Bypass. It's MPLS based (more intelligent than older protocols and better for handling QOS markings). We've been doing it since 2003, using Toll Bypass and implementing voice gateways.

Audience Comment: You can do it with an IP network, but then you don't have QOS capabilities.

Q: Where is the voice gateway in a system like Vonage?

David: There are thousands of ways to do it. They would likely need an endpoint agreement with phone companies in other countries.

Q: What phones do you use at IBM?

David: We use both analog and POE phones. POE phones need more power.

Q: What about security and multimedia?

David: It's an Intranet so it's not accessible to the outside anyway. We are already within our own network. But if I had access, I could sniff out your RTP packets and play it back if it's not encoded. There are some encoding solutions out there. We are currently piloting multimedia. Voice traffic itself is actually very small, requires very little bandwidth. So the most important concerns with voice are dealing with latency, lost packets, and jitter. Video is actually a big jump.

Q: Are there E-911 issues? [Enhanced 911 lets your phone provide automatic location information to the 911 call center]

Eric: E-911 is now required. The main thing is that if you move you have to update your address.

Audience Comment: The E-911 system isn't really built yet, as it has only recently been mandated. There is a problem with mobility. Right now if you call from a cafe, they will send the police to your house. And yet small local ISPs cannot offer VoIP due to E911 requirements.

Eric: Local ISPs generally resell services from the bigger ones.

David: the E-911 standards are in flux.

Audience Comment: What's the big deal? E911 doesn't really work on cell phones anyway.

David: Cisco has a tool that helps identify the location of your IP address to, perhaps, within a building. Again, a lot of this technology is still being built.

Q: Skype is used a lot with smaller companies, and it seems a lot like other free services like Yahoo and Gmail. It seems to work very well, although you occasionally get a bad connection and have to redial.

David: Skype is like IM with a phone.

Eric: Skype is not the same as VoIP.

Q: What about hosted PBX?

Eric: Lots of ISPs do it, and it comes in a variety of flavors. You have to be careful about phone number portability with Skype.

Q: What I need to get started?

Eric: Get a broadband connection, go to my website, order service, and they will ship you a box. If you want to use your home phone wiring, dump your phone company first so you can keep using the same phone number.

Q: What if you have DSL?

Audience Comment: Port your number and then order
naked DSL.

Q: What if you want to keep your existing DSL.

Eric: Just plug your VoIP box into your DSL and use that. It's no problem. Or you can use Skype.

Q: Are there situations where you could not turn off PSTN because you need it for faxing?

David: You can gain analog connectivity with the network--fax over IP works on our Cisco devices. But sometimes cost considerations make you want to keep PSTN. We use centralized call management with PSTNs at each site. Cisco can even deal with outages that let you call without the central manager. Data networks are of course not at the uptime level of POTS phone networks (99.9999...%), so that is a challenge. We are no where near POTS reliability yet.

Q: Can I connect my fax machine to VoIP?

Eric: Yes, you can use your fax machine, but it's not
reliable yet. Pages will get dropped.

Q: Is faxing an issue for home offices then?

Eric & David: Some methods and codecs are better than others for faxing, but it's still a real problem right now.

Q: Can you record VoIP calls?

Eric: There's nothing on the consumer end that I know of.

Audience Comment: There's a Skype add-on.

Q: What tools can you use to analyze service quality?

David: Standard IP sniffing at both ends to make sure your values are being marked properly. We use Spirent SmartBits to put load on the device and see what happens. You can also use ClearSight.

Q: Any problems at IBM?

David: Yes, you can have no audio or one-way audio. But we only get 5-10 trouble tickets per month for thousands of users. It took time to work out the bugs. Most users don't even notice when they get switched over to VoIP. We are redeveloping a lot of codecs to get better quality with lower bandwidth.

Q: Are there QOS challenges with multiple vendors of switches?

David: We use all Cisco, so that helps. Routing protocols are important. You have to put DNS and DHCP at lower priority.

Q: What's your Return On Investment on doing this conversion, considering that phone rates and long distance rates are dropping?

David: Up-front costs can be expensive. A Cisco phone is $400-500 apiece. But the Toll Bypass gives an almost immediate ROI. We're not paying for conference calls any more. The Voice Gateway is also an expense ($2-15k). IBM does millions of minutes per month, so savings are quick. I would say a typical ROI is 2-4 years, but that's just a guess.

Q: Is IBM now competing with the phone companies by selling VoIP services?

David: Yes, once we figure out stuff in-house, we can sell it as a service to our customers. So to a certain extent I guess we are competing with the phone company.

Q: Don't I still have to use Qwest from home?

Eric: Is there something people don't like about Qwest? Yes, to use VoIP you still need an internet connection, either through Qwest, Comcast cable, or some other ISP.

Q: So for us, either Qwest DSL or Comcast cable is required for VoIP--we still have to pay for the line?

David: Yes.

Q: Any advantage to setting up VoIP overseas?

Eric: You can set it up anywhere, but due to infrastructure I think it's better to get it here, and then connect to it overseas.

Audience Comment: Skype might be your best choice for setting up overseas.


RMIUG (www.rmiug.org/) appreciates the sponsorship of
MicroStaff (www.microstaff.com), ONEWARE (/www.ONEWARE.com), and Copy Diva (www.copydiva.com).

Select a Year

2009 Minutes
2008 Minutes
2007 Minutes
2006 Minutes
2005 Minutes
2004 Minutes
2003 Minutes
2002 Minutes
2001 Minutes
2000 Minutes
1999 Minutes
1998 Minutes
1997 Minutes
1996 Minutes
1995 Minutes
1994 Minutes

Copyright 2004 RMIUG.org, All Rights Reserved