1.  Problematic: Transfer of e-mail messages from one server to another. A user is never in direct contact with this server must use an email client which is responsible to contact the server to send or receive messages. 1

2. PostfixApache JamesCourier mail server NetMail SMTPYesNo Yes POP3NoyesYes IMAPNo Yes LicenceOpen source Open SourcePropriétaire 2

3.  Postfix advantage: Powerful Easy to configure (with courier) Free We can also implement secure platforms (TLS and SSL) implementable on Postfix 3

4.  Mail Clients: 4 Advantage Disadvantage Thunderbrid Free, secure, integrated anti- spam does not have built-in help Outoolk Supplied with Windows Main target of virus attacks

5.  VoIP refers to technology that enables routing of voice conversations over the Internet or a computer network.  In the new generation of business networks, both networks (voice and data) are integrated into a single IP-based network.  The enterprise network comprises multiple sites, which are interconnected by a network operator, which may be VPN (Virtual Private Network). 5

6.  Asterisk PBX is a telephone exchange (PABX) open source and proprietary for GNU / Linux systems.  Asterisk implements protocols H.320, H.323 and SIP, and a specific protocol called IAX (Inter-Asterisk eXchange).  Asterisk can also play the role of registrar and gateway with public networks (PSTN, GSM, etc.). 6

7.  The main motivations for deploying IP telephony are cited in the following table: 7 MotivationsPercentage Cost reduction75% Need to standardize the equipment66% Increase employee productivity65% Other benefits of productivity64% Increase the volume of calls to deal46% Other factors50%

8.  Resource optimization  Reduction of installation cost  Transport costs close to zero  Mobility of the user profile  Exclusive services (presence service...)  PDA  Voicemail / E-mail 8

9. There is only one disadvantage: single network, in case of a power outage. => Total paralysis The solution to this problem is self-supply terminals from the Ethernet switch via batteries. 9