Teleworker Services

1. Teleworker Services W.lilakiatsakun

2. Introduction (1) • Teleworking is working away from a traditional workplace, usually from a home office. • The reasons for choosing teleworking are varied and include everything from personal convenience to allowing injured or shut-in employees opportunities to continue working during periods of convalescence.

3. Introduction (2) • Teleworking is a broad term referring to conducting work by connecting to a workplace from a remote location, with the assistance of telecommunications. • Efficient teleworking is possible because of broadband Internet connections, virtual private networks (VPN), and more advanced technologies, including Voice over IP (VoIP) and videoconferencing.

4. Benefit

5. Teleworker Solution (1) • Traditional private WAN Layer 2 technologies, including Frame Relay, ATM, and leased lines, provide many remote connection solutions. • The security of these connections depends on the service provider. • IPsec Virtual Private Networks (VPNs) offer flexible and scalable connectivity.

6. Teleworker Solution (2) • Site-to-site connections can provide a secure, fast, and reliable remote connection to teleworkers. • This is the most common option for teleworkers, combined with remote access over broadband, to establish a secure VPN over the public Internet. • (A less reliable means of connectivity using the Internet is a dialup connection.)

7. Teleworker Solution (3)

8. Teleworking Component (1) • Home Office Components - The required home office components are a laptop or desktop computer, broadband access (cable or DSL), and a VPN router or VPN client software installed on the computer. • Additional components might include a wireless access point. • When traveling, teleworkers need an Internet connection and a VPN client to connect to the corporate network over any available dialup, network, or broadband connection.

9. Teleworking Component (2) • Corporate Components - Corporate components are VPN-capable routers, VPN concentrators, multifunction security appliances, authentication, and central management devices for resilient aggregation and termination of the VPN connections.

10. Teleworking Component (3) • Routers need Quality of Service (QoS) functionality. QoS refers to the capability of a network to provide better service to selected network traffic, as required by voice and video applications..

11. Teleworking Component (4)

12. Connecting teleworkers to WAN (1) • Dialup access - An inexpensive option that uses any phone line and a modem. • Dialup is the slowest connection option • DSL - Typically more expensive than dialup, but provides a faster connection. • DSL also uses telephone lines, but unlike dialup access, DSL provides a continuous connection to the Internet. • DSL uses a special high-speed modem that separates the DSL signal from the telephone signal and provides an Ethernet connection to a host computer or LAN.

13. Connecting teleworkers to WAN (2) • Cable modem - Offered by cable television service providers. • The Internet signal is carried on the same coaxial cable that delivers cable television. • A special cable modem separates the Internet signal from the other signals carried on the cable and provides an Ethernet connection to a host computer or LAN. • Satellite - Offered by satellite service providers. • The computer connects through Ethernet to a satellite modem that transmits radio signals to the nearest point of presence (POP) within the satellite network.

14. Connecting teleworkers to WAN (3)

15. Broadband Services (1)

16. Broadband Services (2) • A cable network is capable of transmitting signals on the cable in either direction at the same time: • Downstream - The direction of an RF signal transmission (TV channels and data) from the source (headend) to the destination (subscribers). (Forward Path) • Downstream frequencies are in the range of 50 to 860 megahertz (MHz). • Upstream - The direction of the RF signal transmission from subscribers to the headend(Reverse Path) • Upstream frequencies are in the range of 5 to 42 MHz.

17. Broadband Services (3)

18. Broadband Services (4) • The Data-over-Cable Service Interface Specification (DOCSIS) is an international standard developed by CableLabs, a non-profit research and development consortium for cable-related technologies.

19. Broadband Services (5) • DOCSIS specifies the OSI Layer 1 and Layer 2 requirements: • Physical layer - For data signals that the cable operator can use, DOCSIS specifies the channel widths (bandwidths of each channel) as 200 kHz, 400 kHz, 800 kHz, 1.6 MHz, 3.2 MHz, and 6.4 MHz. • DOCSIS also specifies modulation techniques (the way to use the RF signal to convey digital data).

20. Broadband Services (6) • MAC layer - Defines a deterministic access method, time-division multiple access (TDMA) or synchronous code division multiple access method (S-CDMA).

21. Cable Modem (1) • Two types of equipment are required to send digital modem signals upstream and downstream on a cable system: • Cable modem termination system (CMTS) at the headend of the cable operator • Cable modem (CM) on the subscriber end

22. Cable Modem (2)

23. Cable Modem (3) • A headend CMTS communicates with CMs located in subscriber homes. • The headend is actually a router with databases for providing Internet services to cable subscribers. • The architecture is relatively simple, using a mixed optical-coaxial network in which optical fiber replaces the lower bandwidth coaxial.

24. Cable Modem (4) • In a modern HFC network, typically 500 to 2,000 active data subscribers are connected to a cable network segment, all sharing the upstream and downstream bandwidth. • The actual bandwidth for Internet service over a CATV line can be up to 27 Mb/s on the download path to the subscriber and about 2.5 Mb/s of bandwidth on the upload path.

25. DSL (1) • The two basic types of DSL technologies are asymmetric (ADSL) and symmetric (SDSL). • ADSL provides higher downstream bandwidth to the user than upload bandwidth. • SDSL provides the same capacity in both directions. • The different varieties of DSL provide different bandwidths, some with capabilities exceeding those of a T1 or E1 leased line. • For satisfactory service, the loop must be less than 5.5 kilometers (3.5 miles).

26. DSL(2)

27. DSL(3) • The two key components are the DSL transceiver and the DSLAM: • Transceiver - Connects the computer of the teleworker to the DSL. • Usually the transceiver is a DSL modem connected to the computer using a USB or Ethernet cable. • Newer DSL transceivers can be built into small routers with multiple 10/100 switch ports suitable for home office use. • DSLAM - Located at the CO of the carrier, the DSLAM combines individual DSL connections from users into one high-capacity link to an ISP, and thereby, to the Internet.

28. DSL (4)

29. DSL (5) • The advantage that DSL has over cable technology is that DSL is not a shared medium. • Each user has a separate direct connection to the DSLAM. • Adding users does not impede performance, unless the DSLAM Internet connection to the ISP, or the Internet, becomes saturated.

30. DSL (6)

31. DSL (7) Microfilter

32. DSL(8) SPLITTER

33. Broadband Wireless (1) • New developments in broadband wireless technology are increasing wireless availability. These include: • Municipal Wi-Fi • WiMAX • Satellite Internet

34. Broadband Wireless (2)

35. Broadband Wireless (3) • Most municipal wireless networks use a mesh topology rather than a hub-and-spoke model. • A mesh is a series of access points (radio transmitters). • Each access point is in range and can communicate with at least two other access points. • The mesh blankets its area with radio signals. Signals travel from access point to access point through this cloud.

36. Broadband Wireless (4) • WiMAX (Worldwide Interoperability for Microwave Access) is telecommunications technology aimed at providing wireless data over long distances in a variety of ways, from point-to-point links to full mobile cellular type access. • WiMAX operates at higher speeds, over greater distances, and for a greater number of users than Wi-Fi.

37. Broadband Wireless (5) • A WiMAX network consists of two main components: • A tower that is similar in concept to a cellular telephone tower. • A single WiMAX tower can provide coverage to an area as large as 3,000 square miles, or almost 7,500 square kilometers. • A WiMAX receiver that is similar in size and shape to a PCMCIA card, or built into a laptop or other wireless device.

38. Broadband Wireless (6) • Satellite Internet services are used in locations where land-based Internet access is not available, or for temporary installations that are continually on the move. • Internet access using satellites is available worldwide, including for vessels at sea, airplanes in flight, and vehicles moving on land.

39. Broadband Wireless (7)

40. Broadband Wireless (8) • One-way multicast satellite Internet systems are used for IP multicast-based data, audio, and video distribution. • One-way terrestrial return satellite Internet systems use traditional dialup access to send outbound data through a modem and receive downloads from the satellite.

41. Broadband Wireless (9) • Two-way satellite Internet sends data from remote sites via satellite to a hub, which then sends the data to the Internet. • The satellite dish at each location needs precise positioning to avoid interference with other satellites.

42. VPN Technology (1) • VPNs provide a virtual WAN infrastructure that connects branch offices, home offices, business partner sites, and remote telecommuters to all or portions of their corporate network. • To remain private, the traffic is encrypted. Instead of using a dedicated Layer 2 connection, such as a leased line, a VPN uses virtual connections that are routed through the Internet.

43. VPN Technology (2)

44. VPN Technology (3) • Benefits : • Cost savings - Organizations can use cost-effective, third-party Internet transport to connect remote offices and users to the main corporate site. This eliminates expensive dedicated WAN links and modem banks. By using broadband, VPNs reduce connectivity costs while increasing remote connection bandwidth.

45. VPN Technology (4) • Security - Advanced encryption and authentication protocols protect data from unauthorized access. • Scalability - VPNs use the Internet infrastructure within ISPs and carriers, making it easy for organizations to add new users. • Organizations, big and small, are able to add large amounts of capacity without adding significant infrastructure.

46. VPN Technology (5)

47. VPN Technology (6) • In a site-to-site VPN, hosts send and receive TCP/IP traffic through a VPN gateway, which could be a router, PIX firewall appliance, or an Adaptive Security Appliance (ASA). • The VPN gateway is responsible for encapsulating and encrypting outbound traffic for all of the traffic from a particular site and sending it through a VPN tunnel over the Internet to a peer VPN gateway at the target site. • On receipt, the peer VPN gateway strips the headers, decrypts the content, and relays the packet toward the target host inside its private network.

48. VPN Technology (7)

49. VPN Technology (7) • In a remote-access VPN, each host typically has VPN client software. • Whenever the host tries to send any traffic, the VPN client software encapsulates and encrypts that traffic before sending it over the Internet to the VPN gateway at the edge of the target network. • On receipt, the VPN gateway handles the data in the same way as it would handle data from a site-to-site VPN.

50. VPN Technology (8)