the 3-14-06 meeting of the Rocky Mountain
Internet Users Group (RMIUG):
"Voice over IP (VOIP): Can You Hear
Copy Diva (www.copydiva.com)
provides the audio-visual equipment
provides the facility
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
INTRODUCTION (Josh Zapin)
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
ABOUT THE SPEAKERS
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
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
Speaker slide presentations are available
VoIP FOR THE HOME AND SMALL OFFICE
VoipReview.org was the first Voice Over
Internet Protocol search engine, detailing
lots of calling plans and providing side-by-side
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
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,
- 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
- 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.
HOW TO PICK A VoIP SERVICE
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 IMPLEMENATATION TECHNOLOGY (AT IBM)
VoIP is important in the corporate, big
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,
Plain Old Telephone Service
When voice is enabled on IP network, a
voice into IP data.
Pick up a handset, dial a number, number
Cisco Call Control Manager (CCM) cluster,
server converts phone number to IP address
of recipient, and rings the recipient's
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
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.
BENEFITS OF A VoIP NETWORK
- Cost savings (+ using combined infrastructures)
- Flexibility: mobility, conferencing
- High Performance: including video conferencing
ENEMIES OF PACKETIZED VoIP SYSTEMS
Delay: Latency delays can be nasty with
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
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
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.
GATEWAY CONTROL PROTOCOLS
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
Q & A
NOTE: David James, a VoIP Architect
with IBM, joined June and Eric for the panel
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
Eric: I think everything will eventually
be VoIP. Management is becoming faster and
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
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
Audience Comment: You can do it
with an IP network, but then you don't have
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
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
Audience Comment: What's the big
deal? E911 doesn't really work on cell phones
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
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
Q: What if you want to keep your
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
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
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
Q: What tools can you use to analyze
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
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
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
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
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
Q: So for us, either Qwest DSL or
Comcast cable is required for VoIP--we still
have to pay for the line?
Q: Any advantage to setting up VoIP
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.
appreciates the sponsorship of
and Copy Diva (www.copydiva.com).