Wireless and VOIP at a remote Orphanage in Honduras

1
Wireless and VOIP at a remote Orphanage in
Honduras

• Charles Ellis
• Director Alabama Micro/Nano Science and
  Technology Center (AMSTC) Laboratory
• Research Faculty Electrical Computer
  Engineering
• March 24, 2007

2
Orphanage Emmanuel Guiamaca, Honduras
2nd largest Orphanage in Honduras 450 Children
from all backgrounds and circumstances.
Supported totally from individual donations (65
from US and 35 from other countries). Totally
dependent on volunteer staff.
3
Auburn Connection

• Local church college mission trip to help with
  construction projects in 1999.
• Continued involvement taking 30 60 Auburn
  college students per year. Next trip may 8th
  15th (32 students).
• Two Auburn graduates are now permanent staff
  members.
• Auburn engineering daily monitoring network
  operation and traffic.
• Actively recruiting short term and long term
  volunteers among Auburn students.
• Local church provides two 1200 scholarships for
  Auburn students willing to commit at least one
  semester as a volunteer.

4
Why is Internet and VOIP needed at a Remote
Orphanage?

• Educational
• Computer laboratory
• Reference
• Remote classrooms
• Webcasts
• Teacher training curriculum development

• Medical
• Remote communication with Doctors
• Medical reference
• Supply Ordering

• Misc
• Staff/Volunteer Communication with family and
  friends
• Administration (i.e. email, online banking,
  software updating)
• Website development (www.orphanageemmanuel.com)

5
Technology History at Orphanage Emmanuel
1998 Two non-networked computers in
administrative offices dial up internet on very
unreliable and expensive (0.50/min) State-run
phone system. 1999 Cat 5 connected (500ft) 2
computers to allow Quickbooks sharing. 2001
Setup computer lab in school consisting of 20
windows based computers (non-networked).
6
2003 Contracted with Direcway to install a
satellite dish (1.2 meter) for internet
connection (300/month) very slow, but
provided a stable internet service. VOIP was not
possible due to excessive drops and reroutes.
7
Problem

• Cat-5 wires keep being cut.
• Remote locations to far for running cat-5 cables

8
Wireless Internet Equipment/Cost
15dBi 2.4GHz OMNI DIRECTIONAL ANTENNABRAND NEW
(Ebay - 100)Omni15 Antenna specsFrequency
2.4-2.5GHz Gain 15dBi Polarization Vertical
Horizontal Beamwidth 360 degreeVertical
Beamwidth 8 degree VSWR lt 1.5 1 Max Power
100 watts Lightning Prot DC groundStandard
Connector N-type female (50 ohm) Material White
FiberglassOperating Temperature -40C to 70C
Length 40.5in (103cm) Weight 3.3lb
(1.5kg)Mounting 2.0in (5.1cm) max. diameter
mast Includes mounting hardware 2 aluminum
brackets, 2 U-bolts 2.7 in (6.9cm)
100 on Ebay
YDI Etherant II LR internet antenna 150 on Ebay
YDI AP Plus Access Point 150 on Ebay
9
2004 Installed YDI Wireless Access point with
omni antenna, 5 YDI etherant II unidirectional
antennas w/ imbedded router.
10
Problem

• State-run Phone service is very unreliable
• Need a US phone number to allow incoming calls
• Regular calls to Honduras are very expensive
  (0.48/min)

11
2004 Installed VOIP PBX system (Asterisk/Linux
Based Server).
Mark Spencer holds a degree in Computer
Engineering from Auburn University, and is now
CTO and Chairman of the Board of Digium, Inc. He
has also led the creation of several Linux-based
open source applications, most notably Asterisk,
the Open Source PBX, and Gaim Instant Messenger.
Contracted with Iconnecthere VOIP service to
provide phone termination and a Stateside phone
number (unlimited calls to and from the US for
29.99/month).
Internal and external extensions
2007-03-22 135851 cafe2 2000 answered 0.1
2007-03-22 142308 13347500734 6 answered 4.3
2007-03-23 083120 Office 2013 answered 3.3
2007-03-23 111534 13347500734 14234434337 answered 0.2
2007-03-23 111724 13347500734 3 answered 0.4
2007-03-23 155438 Anonymous 4 answered 1.1
2007-03-23 172726 Anonymous 4 answered 36.5
2007-03-23 200744 wade 12563954361 answered 4.3
12
Problem
Volunteers and members of the local community
want internet access
13
2004 Setup an internet café with 5 computers.
14
Problem
Direcway does not seem to allow reliable VOIP
service Latency There is approximately 280 msec
of one-way propagation delay due to the location
of the Geo Stationary orbit and the speed of
light. Regardless of the satellite product, this
propagation delay must be considered and
overcome. Today, numerous overseas calls
originated in the United States are actually
transmitted as VoIP over satellite calls,
particularly if provided by the smaller long
distance carriers. Required bandwidth per VoIP
call To design a network properly, one would need
to know the amount of bandwidth required per VoIP
call, the number of concurrent calls, and the
duration of the call. Bandwidth required per VoIP
call will depend the encoding standard used,
header compression, and payload size. For
example, with G.729(b), payload of 40 bytes, and
no header compression, a VoIP call would take
about 16Kbps of bandwidth. With header
compression this would require 10Kbps of
bandwidth. Jitter Quantifies the effects of
network delays on packets arriving at the
receiver. Packets transmitted at equal intervals
from the transmitting gateway arrive at the
receiving gateway at irregular intervals.
Excessive jitter has the effect of making speech
choppy and difficult to understand. Jitter is
calculated based on the inter-arrival time of
successive packets. For high-quality voice, the
average inter-arrival time at the receiver should
be nearly equal to the inter-packet gaps at the
transmitter and the standard deviation should be
low. Jitter buffers (packet buffers that hold
incoming packets for a specified amount of time)
are used to counteract the effects of network
fluctuations and create a smooth packet flow at
the receiving end. Packet Loss Packet loss or
packet corruption will cause degradation of voice
quality. Since all of the voice traffic is UDP/IP
and would not be retransmitted (like in the case
of TCP/IP) all packets would be completely lost
if the packet becomes lost or corrupted. It is
extremely important to have very low Bit Error
Rates (BER) to ensure low or no corruption or
loss.
15
Comparing Satellite Platforms

• Hughes DirecWay - Legacy TDMA standard
• Many of sharing techniques are based on TDMA
  which stands for Time Division Multiple Access
  technology and usually are variants of TDMA. Most
  primitive (legacy) technologies allow users to
  transmit randomly, decreasing the overall
  performance of the network down to almost 15-20
• iDirect NetModem and Infiniti Series Routers -
  Deterministic TDMA standards
• iDirect Corporation propriteary Deterministic
  TDMA, dedicate timeslots to every subscriber,
  raising the performance bar at near 98.

16
Skycasters Service Plans
Service Level Throughput Allowance CIR Monthly Pricing
1.5Mbps/200Kbps 500MB 1.02Mbps/ 96Kbps 99.00
                               
1.5Mbps/384Kbps 1.0GB 1.02Mbps/ 128Kbps 149.00
                                       
2.04Mbps/512Kbps 2.0GB 1.02Mbps/ 256Kbps 199.00
                                       
2.04Mbps/640Kbps 3.0GB 1.5Mbps/ 384Kbps 249.00
                                       
2.50Mbps/786Kbps 5.0GB 1.5Mbps/ 512Kbps 399.00
                                       
2.5Mbps/1.02Mbps 7.0GB 2.04Mbps/ 768Kbps 499.00
                                       
3.07Mbps/1.5Mbps 15.0GB 2.04Mbps/ 1.02Mbps 999.00
CIR The CIR connection speed is the speed in
which we commit data can be transferred. Several
variables can affect your connection speed such
as number of concurrent connections on your LAN,
QoS priorities, and overall network congestion.
You can expect the ability to receive at least
90 of the stated CIR speeds 90 of the time, if
not more!
Service Level - This is the maximum connection
speed potential at any given time, which is also
affected by the same variables listed above.
17
2005 Purchased/ shipped/ installed a VSAT
satellite dish (1.8 meter with 4 watt BUC)
/iDirect Net Modem Plus pointed at AMC-6
Satellite.
Cost 3500
AMC-6 Ku-Band Launched on 22 October 2000, AMC-6
became the fifth hybrid C/Ku-band satellite in
the AMERICOM fleet. From it's position in the
eastern part of the U.S. orbital arc, AMC-6
provides high-powered service to occasional
video/SNG, government, VSAT network and
entertainment customers.
18
Problem
Bandwidth Usage Plan -gt 1M down 512K up We
are allowed 2 G/month from Skycasters (199) We
are using 3-6 G/month If we go over the
monthly allotment we are throttled back to
Dialup speeds 56k (usually happens anywhere
from the 15th to the 20th of the month) No
more VOIP or large file downloading We need a
way to monitor the internet traffic
19
2005 Installed a Netgear managed switch And a
Linksys router w/QOS
Website Interface to Switch
20
Problem
New Construction New staff housing needs
internet access and phone service
21
2006 Installed Linksys bridge and four sets of
access points and PAP2 SIP based phone adapters
in new staff quadruplex.
22
Problem
Bandwidth Usage Plan -gt 1M down 512K up We
are allowed 2 G/month from Skycasters (199) We
are using 3-6 G/month If we go over the
monthly allotment we are throttled back to
Dialup speeds 56k (usually happens anywhere
from the 15th to the 20th of the month) No
more VOIP or large file downloading We have
determined that the heavy bandwidth usage is
coming from the wireless connection, but which
computer is the culprit? We need packet
monitoring!
23

• 2007 Added internet monitoring using a linux
  server included a backup Asterisk phone server.

Determined some of the college aged volunteers
were leaving laptops on with P2P and Skype
running. After figuring out which ones, we were
able to cut bandwidth usage by 60. All
volunteers and staff were asked to cut off
computers when not in use. Also, the volunteers
were limited to only having access to the
internet between 9 and 10 PM. This is done
through the routers internet access settings.
Fri Mar 23 232210 2007 2 129 ---
out-out --- 2 117 192.168.1.255 1
94 192.168.1.98 1 35
192.168.1.102 0 6 198.77.116.8 0
6 198.77.116.12 1 94
192.168.1.98 -gt 192.168.1.255 0 23
192.168.1.102 -gt 192.168.1.255 0 6
192.168.1.102 -gt 198.77.116.12 0 6
192.168.1.102 -gt 198.77.116.8
24
Summary
Provided stable managed internet to Orphanage
Emmanuel. Installed a wireless internet
system. Established a working internet café with
phone service. Installed a VOIP system allowing
free calls to and from the US and inexpensive
calls to the rest of the world (i.e. 2.3
cents/min to Denmark) Provided packet monitoring
system
Whats Next?
Local DNS and Web caching Live CDs for the
Internet Café (Knoppix type Linux CDs) Provide
replacement hardware for all components More
wireless points as Orphanage Grows may go to
1000 kids! (already serving 1300 meals a day!)