TCP/IP - Going into business with VoIP

(4 dagar)

Introducting Voip Class

This is a class for the newcomer, althought it is good to have some experience working with PC's. It is not nessesary to have knowledge of computer network's and IP.

The class will teach the basic understanding of how VoIP (Internet based telephony)

works in Theory and practise. Class is mixed 40% Theory and 60% practise. All exercises and labs are done in realistic real world network enviroments with the latest most stable available technology.

During the class you will learn howto plan you VoIP network.

You will also install learn howto configure and install VoIP equipment, first in your controlled enviroment. After you learn more during the class you will head common real life situations similar to your customers network enviroment. You will learn to avoid common pitfalls in forehand. Also class will learn you howto find and correct most common errors

that arrives during installation and in production.

All classes are built of theory blocks, and practise blocks.

Slides and whiteboard are used by theachers, studends have one PC each

plus copy of slides and classroom books.



VoIP Moment - chapter

DAY 1)

1. Theory Physical network enviroment

2. Practise Physical network enviroment, wiring the VoIP devices

DAY 2)

3. Theory TCP/IP

4. Practise TCP/IP, connecting VoIP devices level 1

DAY 3)

5. Theory How VoIP works

6. Practise How VoIP works, connecting VoIP devices level 2

DAY 4)

7. Teory Purpose of NAT and its effects on VoIP protocols.

8. Practise NAT connecting VoIP devices level 3

9. Theory Purpose of Firewalls and its effects on VoIP protocols.

10. Practise Firewalls connecting VoIP devices level 4

11. Exam and Certification

1. Theory Physical network enviroment
How IP and its transport layers works.

  1. Data link physical (cables, connectors, switches and bridges)Different kind of networks: bus, star, ring, mesh.
  2. Network (the internet layer ontop of all cables)
  3. Transport (howto transport data over internet)
  4. Application (what you want to do with the data, voice, email, etc.)
  5. What is bandwith/broadband ADSL/Cable/Analog modem?
  6. Wireless networks WiFi and OFDM.
  7. Internet over PowerLine

2. Practise Physical network enviroment wiring the VoIP devices
Physically connect PC's and Adapters to router and switch. Purpose is to learn getting the physical network correctly connected.

  1. Identify and understand difference between bridge, switch, router.
  2. Identify different cables like TP strait and crossover, coax and fibre.
  3. Making TP cables strait and crossover.
  4. Identify cable trouble. Find ports, what is WAN and LAN ports.
  5. What the LED'S mean ? Link up/Link down
  6. Experience effects of bandwith problems.
  7. Looking at wireless technology,
    Setting up a small WiFi lab net and connect
    WiPhone to it.
    Securing the WiFi with WEP and SSID.
  8. Looking at Internet over powerline
    Setting up a two PLM and connecting
    phones to it.
    Securing PowerLine distributed traffic.

3. Theory TCP/IP
Basic IP protocols and their fundamental functions.
Purpose is to have understanding on TCP/IP in order to be able configuring devices and avoid problems.

  1. arp (binding datalink physical to ip addresses)
  2. ip (addressing, public and private)
  3. icmp (ping, traceroute, latency)
  4. tcp / udp (data transport systems)
  5. Common port's (Services and application connections)
  6. dhcp (Automatic configuration delivery to clients from servers)
  7. dns (purpose of nameserver, what is you logical name ?)
  8. Plug and Play
  9. Quality of Service.

4. Practise TCP/IP connecting VoIP devices
In this exercise's you will learn how to configure your network equipment and some tricks making it easy. This is known as IP administrating by use of IP toolkit.

  1. How to check and configure devices IP address and IP parameters.
    Checking the devices current IP address and adding IP address manually.
  2. Checking that hardware and logical is binded correctly using ping and arp.
  3. Learn in practise "default router" and dns using nslookup and traceroute.
  4. Checking that devices reach eachother and out on the internet to our servers.
  5. Learn howto configure/repair/correct/check DHCP and static IP for:
    1. Windows XP and microsoft family
    2. Softphone
    3. Hardphone
    4. Adapter (ATA)
  6. Looking further on the WiFi network devices settings. DHCP and Wireless issues.
  7. Looking further on the PowerLine network devices settings. PowerLine network and DHCP issues.

5. Theory How VoIP works
You will in this master learn how VoIP works and why it wont work in some cases. We look on standards used, the pros and cons of them.
How codecs work and why they are needed and the side effects of them.
Transcoding between VoIP protocols, why and when.


  1. Phone goes digital:
    Web login
    Voicemail account
    Web password
    Password Account serial number
  2. Codecs: G729, G7321 and GSM
  3. What is h323, sip, iax2
  4. What does the Gatekeeper and Proxy do
  5. Purpose of the Gateway
  6. The CDR and analysis
  7. How VoIP signalling works
  8. Some brands, Mera, Asterisk, GnuGK and Dialogic.
  9. Video protocols and cams for two way Videocalls.
  10. Call routing/Prefixes.
  11. IVR systems.
  12. How billing is made from CDR.
  13. Ratetables in DTL.

6. Practise How VoIP works connecting VoIP devices level 2
Purpose of this exercise is get known to VoIP equipment and their needs.
You also learn how to track down problems and fix them as well as give support.

  1. Installing and configuring Adapter VoIP parameters to work with SIP classroom and real server.
    Secure and Failchecking Adapter and restore lost settings.
  2. Installing and configuring Hardphone VoIP parameters to work with H323, SIP and preferred IAX2 classroom and real server.
    Secure and failchecking hardphone and restore lost settings.
    Upgrade firmware and change firmware from H323 to SIP or IAX2 in hardphone.
    Changing ringtones in hardphone.
  3. Installing and configuring Softphone VoIP parameters to work with H323 server.
  4. Making calls, testing prefixes, checking CDR's in classroom server, looking at LEDS and control panels.
  5. Installing your own gatekeeper from scratch and connect your phone to it. Making calls and checking CDR.
  6. Interconnecting gatekeepers.

7. Teory Purpose of NAT and its effects on VoIP protocols.
Now when you are familiar with VoIP it is time to head real life with NAT.

  1. How NAT server is operating. Public address translated to private address.
    TCP-UDP Keep alive chains and connection internal timeouts.
    Stateful NAT router, non stateful will not work well at all.
  2. Why NAT makes problem for VoIP traffic.
    H323 need portforwarding of 2 ports.
    SIP need keep alive or portforwarding of 1 port. IAX2 almost allways work anyway.
  3. Configuring NAT servers, portforwarding/Virtual server/Napt
    Portforwarding make one way sound go away. Portforwarding Making incoming calls work. Deligate ports to phones.
  4. Some brands of NAT routers; D-Link, Zyxel, Telewell, Alcatel, Speedtouch..
  5. Proxy NAT to help VoIP.

8. Practise NAT connecting VoIP devices level 3
The exercise will show you what you meet in real life situations and how to make VoIP work behind NAT, even the server behind NAT.

  1. Setting UP NAT routers
  2. Setting up H323 Phone/Softphone devices behind nat.
  3. Setting up SIP Adapter/Hardphone devices behind nat.
  4. Setting up IAX2 Adapter/Hardphone devices behind nat.
  5. Troubleshooting NAT issues with phone itself and NAT router logfiles.
    Portforwarding is missing or faulty
    Phone NAT settings is wrong.
    NAT router is NOT stateful what now do I do ?
  6. Proxy NAT.

9. Theory Purpose of Firewalls and its effects on VoIP protocols.
Firewalls are here to protect us, but can ruin our business if we do not understand them. You will learn how to configure basic firewall and at the same time make VoIP work.

  1. Filtering on IP traffic rules.
  2. Application filtering the evil thing.
  3. Stateful / non stateful firewalling.

10. Practise Firewalls connecting VoIP devices level 4
At first insight this make seems like everyone has a firewall, in fact, most have just NAT and portforwarding and no firewalls. It is not so dangerous as it might look like, because NAT prevent most illegal traffic.

  1. Checking Firewall rules
  2. Allowing traffic to and from our servers
  3. Allowing traffic from our phones to servers
  4. Setting up H323 Phone/Softphone devices and firewalls.
  5. Setting up SIP Adapter/Hardphone devices and firewalls.
  6. Setting up IAX2 Adapter/Hardphone devices and firewalls.
  7. Troubleshooting Firewall issues and Firewall logfiles.
    Firewall SPI rules
    Firewall DOS rules
    Blocked traffic
    None stateful firewall

11. Exam and Certification
After fullfilling class an exam is performed:
Teory 10 questions
2 Practical tests.

90% correct in teory and both practical tests correctly performed will result in VoIP certified engineer.