Wireless and VOIP at a remote Orphanage in Honduras

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

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.

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.

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)

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).

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.

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

Wireless Internet Equipment/Cost 15dBi 2.4GHz OMNI DIRECTIONAL ANTENNABRAND NEW (Ebay - $100)Omni15 Antenna specs:•Frequency: 2.4-2.5GHz •Gain: 15dBi •Polarization: Vertical •Horizontal Beamwidth: 360 degree•Vertical Beamwidth: 8 degree •VSWR: < 1.5 : 1 •Max Power: 100 watts •Lightning Prot: DC ground•Standard Connector: N-type female (50 ohm) Material: White Fiberglass•Operating Temperature: -40°C to +70°C •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

2004 – Installed YDI Wireless Access point with omni antenna, 5 YDI etherant II unidirectional antennas w/ imbedded router.

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)

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

Problem Volunteers and members of the local community want internet access

2004 – Setup an internet café with 5 computers.

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.

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%.

Skycasters Service Plans *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.

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.

Problem Bandwidth Usage : Plan -> 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

2005 – Installed a Netgear managed switch – And a Linksys router w/QOS Website Interface to Switch

Problem New Construction – New staff housing needs internet access and phone service

2006 – Installed Linksys bridge and four sets of access points and PAP2 SIP based phone adapters in new staff quadruplex.

Problem Bandwidth Usage : Plan -> 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!

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 router’s internet access settings. Fri Mar 23 23:22:10 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 -> 192.168.1.255 0 23 192.168.1.102 -> 192.168.1.255 0 6 192.168.1.102 -> 198.77.116.12 0 6 192.168.1.102 -> 198.77.116.8

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 What’s Next? Local DNS and Web caching Live CD’s for the Internet Café (Knoppix type Linux CD’s) Provide replacement hardware for all components More wireless points as Orphanage Grows – may go to 1000 kids! (already serving 1300 meals a day!)

Wireless and VOIP at a remote Orphanage in Honduras