1. Chapter 3: Planning Network Protocols and Compatibility

2. Learning Objectives
Explain basic network concepts, including network terms, types of networks, and network cards
Explain the NDIS and ODI network driver specifications
Explain the communications protocols used in Windows 2000 Server, including TCP/IP, NWLink, NetBEUI, DLC, and AppleTalk
LastUpdated
P. Kyser TCM343

3. Learning Objectives (continued)
Plan network binding order, change the binding order, and bind and unbind protocols
Plan how to implement protocols on different types of networks
LastUpdated
P. Kyser TCM343

4. Protocol A protocol consists of guidelines for:
How data is formatted into discrete units called packets and frames
How packets and frames are transmitted across one or more networks
How packets and frames are interpreted at the receiving end
LastUpdated
P. Kyser TCM343

5. Packets and Frames
Packets and frames are units of data transmitted from one networked computer or device to another.
Although packets and frames are often used to have the same meaning, there is a difference. Packets operate at a higher communication layer and contain routing information.
LastUpdated
P. Kyser TCM343

6. General Sections in Packets and Frames
Header
Data
Trailer or footer
LastUpdated
P. Kyser TCM343

7. Packet and Frame Format
Figure 3-1 Basic packet and frame format
LastUpdated
P. Kyser TCM343

8. Network Design The basic design of a network is its topology
Topology: The physical layout of the cable and the logical path followed by network packets and frames sent on the cable
Bus
Ring
Star
LastUpdated
P. Kyser TCM343

9. Ethernet and Token Ring
Ethernet: A network transport system that uses a carrier sensing and collision detection method to regulate data transmissions
Token ring: A network transport method that uses a token, which is passed from node to node, to coordinate data transmissions
LastUpdated
P. Kyser TCM343

10. Local Area Network
Local area network (LAN): Joins computers, printers, and other computer equipment within a limited service area and generally employs only one topology
LastUpdated
P. Kyser TCM343

11. Figure 3-2 A LAN in a building
Example of a LAN
Figure 3-2 A LAN in a building
LastUpdated
P. Kyser TCM343

12. Metropolitan Area Network
Metropolitan area network (MAN): A network that links multiple LANs within a large city or metropolitan area
LastUpdated
P. Kyser TCM343

13. Example of a MAN MAN connecting buildings in a city
University chemistry
building
Research hospital
Pharmaceutical company
MAN connecting buildings in a city
LastUpdated
P. Kyser TCM343

14. Enterprise Network Enterprise Network:
A network that often reaches throughout a large area, such as a college campus, a city, or across several states.
A distinguishing factor of an enterprise network is that it brings together an array of network resources such as many kinds of
servers,
mainframes,
printers, network devices,
intranets, and the Internet
LastUpdated
P. Kyser TCM343

15. Typical Resources in an Enterprise Network
Figure 3-3
Resources in an
enterprise network
LastUpdated
P. Kyser TCM343

16. Wide Area Network
Wide Area Network (WAN): A far-reaching system of networks that can extend across state lines and across continents
LastUpdated
P. Kyser TCM343

17. Example of a WAN WAN across a continent LastUpdated 20040321
P. Kyser TCM343

18. Network Interface Card Communication Medium Options
Coaxial cable (thick and thinnet)
Twisted-pair (shielded and unshielded)
Fiber-optic
Wireless (infrared, radio wave, microwave, satellite)
LastUpdated
P. Kyser TCM343

19. Connecting a Medium to a NIC
Figure 3-4 Connecting cable to a NIC
LastUpdated
P. Kyser TCM343

20. Device Address
Each NIC has a physical or device address that is burned into a PROM on the card
Media access control (MAC) address is another way of describing the device address
LastUpdated
P. Kyser TCM343

21. Device Address
LastUpdated
P. Kyser TCM343

22. MS - NDIS (Start Here) Simultaneous-Multiple Protocols
Network Driver Interface Specification (NDIS): A set of standards developed by Microsoft and 3COM for network drivers that enables communication between a NIC and a protocol, and that enables the use of multiple protocols on the same network
LastUpdated
P. Kyser TCM343

23. Figure 3-5 Binding a protocol to a NIC
NDIS Architecture
Figure 3-5 Binding a protocol to a NIC
LastUpdated
P. Kyser TCM343

24. Novell – ODI Simultaneous-Multiple Protocols
Open Datalink Interface (ODI) driver: A driver that is used by Novell NetWare networks to transport multiple protocols on the same network
Found on some older MS networks
Best to convert older systems to NDIS before upgrading to Win2000
LastUpdated
P. Kyser TCM343

25. Microsoft-Supported Communication Protocols
LastUpdated
P. Kyser TCM343

26. Microsoft-Supported Protocols (continued)
LastUpdated
P. Kyser TCM343

27. TCP/IP
Transmission Control Protocol (TCP) portion performs extensive error checking to ensure that data is delivered successfully
Internet Protocol (IP) portion consists of rules for packaging data and ensuring that it reaches the correct destination address
LastUpdated
P. Kyser TCM343

28. TCP/IP A Protocol Well-suited for medium and large networks
Designed for routing; has high degree of reliability
Used worldwide for directly connecting to the Internet and by Web servers
Enables lower TCO on Microsoft networks
LastUpdated
P. Kyser TCM343

29. PROs/CONs TCP/IP not a true international standard
But has evolved as a de facto standard
ease of configuration, maintenance, scaled
flexible
Good error detection/recovery
Global acceptance/broad appeal
OSI is Global, but implementations at each layer causes incompatibilities between different networks
LastUpdated
P. Kyser TCM343

30. TCP/IP Advantages
Compatible with standard tools for analyzing network performance
Parallel ability to use DHCP and WINS through a Windows 2000 server
Ability for diverse networks and operating systems to communicate
Compatible with Microsoft Windows Sockets
LastUpdated
P. Kyser TCM343

31. TCP/IP Disadvantages
More difficult to set up and maintain than other protocols
Somewhat slower than IPX/SPX and NetBEUI on networks with light to medium traffic
LastUpdated
P. Kyser TCM343

32. UDP (connectionless TCP)
OSI
Application
FTP
Telnet
SMTP
HTTP
SNMP
RTP
Presentation
Sesion
Transport
TCP
UDP (connectionless TCP)
Network
Internet Protocol
ARP
Datalink
Ethernet
ATM
Token ring
Physical
Physical Layer
FTP File Transfer Protocol
SMPT Simple Mail Transport Protocol
HTTP Hypertext Transmission Protocol
DNS Domain Name Service
ARP Address Resolution Protocol
TELNET Terminal Emulation
SNMP Simple Network Management Protocols (UDP)
RTP Real-time Transport (UDP)
TCP Transmission Control Protocol
IP Internat Protocol
IPv4 IPv6
VoIP Voice over IP
VoFR Voice over frame relay
UDP User Datagram Protocol
HTTP Hypertext Transmission Protocol
DNS Domain Name Service
ARP Address Resolution Protocol

33. TCP TCP/IP Not part of Datalink and Physical Layers
TCP is analogous to the OSI transport layer
Connection must me established before data flow
guaranteed delivery
end-to-end error checking / correction / acknowledgement ensures data is transmitted error free
TCP packet format:
Src Addr
Dest Addr
Cntrl Infor
CRC
Urgency
Options
Payload 
2 bytes
TCP
12 bytes
Header 
Variable
variable
LastUpdated
P. Kyser TCM343

34. UDP User Datagram Protocol (UDP) is connectionless version of TCP
Flow can occur before connection sessions are established
CON-Less reliable
PRO-Less overhead
If reliability established at higher levels, is more efficient than TCP
LastUpdated
P. Kyser TCM343

35. IP IP is analogous to the OSI network Layer
segments and packets data for transmission
adds header for delivery
Header is in addition to TCP/UDP header appended to the application data
Includes Dest and Src address ensuring end-to-end data flow
Each network node reads the header info and properly routes the packet
No check for or assurance of delivery
LastUpdated
P. Kyser TCM343

36. IP No relationship between Layer 2 address and IP address
When IP data is delivered to LAN:
AN ARP (address resolution Protocol) is required to enable data to reach its destination
Physical machine address (MAC address)
ARP provides rules for making the correlation between IP to MAC and MAC to IP addresses
LastUpdated
P. Kyser TCM343

37. IP
IP routing specifies that IP datagrams travel through internetworks one-hop-at-a-time
The entire route is not know at the beginning of the journey
At each stop, the destination is calculated by matching the destination address within the datagram with an entry in the current nodes routing table. (Dynamic routing)
Each nodes involvement is to forward packet based on its own knowledge
IPv4
Header and ctrl info
CRC
Source Addr
Dest Addr
Options
Payload
10 bytes
2 bytes
4 bytes
variable
LastUpdated
P. Kyser TCM343

38. Dotted Decimal Notation
Dotted Decimal Notation: An addressing technique that uses four octets, such as , converted to decimal (e.g., ), to differentiate individual servers, workstations, and other network devices.
LastUpdated
P. Kyser TCM343

39. Multicasting, single packet to multiple sources (UDP only)
IP Addressing
Experimental 1
Class E
Multicast Address
Class D
Host Portion
Network Portion
Class C
Class B
Network
Class A
32 Bits
Experimental 1
Class E
Multicast Address
Class D
Host Portion
Network Portion
Class C
Class B
Network
Class A
32 Bits
Experimental 1
Class E
Multicast Address
Class D
Host Portion
Network Portion
Class C
Class B
Network
Class A
32 Bits
Experimental 1
Class E
Multicast Address
Class D
Host Portion
Network Portion
Class C
Class B
Network
Class A
32 Bits
Experimental 1
Class E
Multicast Address
Class D
Host Portion
Network Portion
Class C
Class B
Network
Class A
32 Bits
Experimental 1
Class E
Multicast Address
Class D
Host Portion
Network Portion
Class C
Class B
Network
Class A
32 Bits
Experimental 1
Class E
Multicast Address
Class D
Host Portion
Network Portion
Class C
Class B
Network
Class A
32 Bits
Future Use
Experimental 1
Class E
Multicasting, single packet to multiple sources (UDP only)
Multicast Address
Class D
Smaller Organization
Network Portion
Class C
Large Organizations
Class B
Very Large Networks
Host Portion
Network
Class A
32 Bits
32 Bits
Cl A
Network
Host Portion
128 Network 16.78M Hosts
Very Large Networks
Cl B 1
Network Portion
16.3k network 65.5k Hosts
Large Organizations
Cl C
2M Networks, 256 hosts
Smaller Organization
Cl D
Multicast Address
Multicasting, single packet to multiple sources (UDP only)
Cl E
Experimental
Future Use
LastUpdated
P. Kyser TCM343

40. Dotted Decimal Notation
4 Decimal Number separated by periods
Internet Assigned Number Authority (IANA) responsible for
Assigning IPs
Running Root servers that provide base for Domain Name Service (DNS)
Final arbitrator for standards
LastUpdated
P. Kyser TCM343

41. Subnet Mask
Subnet mask: A designated portion of an IP address that is used to indicate the class of addressing on a network and to divide a network into subnetworks as a way to control traffic and enforce security
Class A
Class B
Entire 3rd oct designated subnet ID (255)
Class B
1st 5 bits of 3rd oct designated subnet ID (248)
LastUpdated
P. Kyser TCM343

42. Unicasting and Multicasting
In a unicast, a transmission is sent to each client that requests a file or application, such as a multimedia presentation
In a multicast, a transmission is sent to all requesting clients as a group (reducing the total network traffic)
LastUpdated
P. Kyser TCM343

43. Unicasting and Multicasting Compared
Figure 3-6 Unicasting compared to multicasting
LastUpdated
P. Kyser TCM343

44. Configuring the IP Address and Subnet Mask in Windows 2000
Figure 3-7 IP address and subnet mask setup
LastUpdated
P. Kyser TCM343

45. Static and Dynamic Addressing
Dynamic addressing: Involves automatically assigning an IP address to a network host
Static addressing: Involves manually assigning an IP address to a network host
LastUpdated
P. Kyser TCM343

46. Routing via TCP/IP Figure 3-8 Router forwarding packets to a
designated network
LastUpdated
P. Kyser TCM343

47. Planning Tip
For medium and large sized networks, plan to use TCP/IP because it enables you to manage and secure network traffic through creating subnets
LastUpdated
P. Kyser TCM343

48. UDP (connectionless TCP)
OSI
Application
FTP
Telnet
SMTP
HTTP
SNMP
RTP
Presentation
Sesion
Transport
TCP
UDP (connectionless TCP)
Network
Internet Protocol
ARP
Datalink
Ethernet
ATM
Token ring
Physical
Physical Layer
FTP File Transfer Protocol
SMPT Simple Mail Transport Protocol
HTTP Hypertext Transmission Protocol
DNS Domain Name Service
ARP Address Resolution Protocol
TELNET Terminal Emulation
SNMP Simple Network Management Protocols (UDP)
RTP Real-time Transport (UDP)
TCP Transmission Control Protocol
IP Internat Protocol
IPv4 IPv6
VoIP Voice over IP
VoFR Voice over frame relay
UDP User Datagram Protocol
HTTP Hypertext Transmission Protocol
DNS Domain Name Service
ARP Address Resolution Protocol

49. Protocols and Applications in the TCP/IP Suite
LastUpdated
P. Kyser TCM343

50. Protocols and Applications in the TCP/IP Suite (continued)
LastUpdated
P. Kyser TCM343

51. Protocols and Applications in the TCP/IP Suite (continued)
LastUpdated
P. Kyser TCM343

52. Protocols and Applications in the TCP/IP Suite (continued)
LastUpdated
P. Kyser TCM343

53. Protocols and Applications in the TCP/IP Suite (continued)
LastUpdated
P. Kyser TCM343

54. IPX/SPX A Protocol
IPX: A protocol developed by Novell for use with its NetWare server operating system (particularly for NetWare versions before version 5)
SPX: A Novell connection-oriented protocol used for network transport when there is a particular need for data reliability
Netware now uses TCP/IP not IPX/SPX
LastUpdated
P. Kyser TCM343

55. MS NWLink A Protocol
A network protocol that simulates the IPX/SPX protocol for Microsoft Windows 95, 98, NT, and 2000 communications with Novell NetWare file servers and compatible devices
LastUpdated
P. Kyser TCM343

56. When to Use NWLink
To enable a computer running Windows 2000 to access a NetWare server (pre-version 5)
To set up Windows 2000 as a gateway to a NetWare server
To enable NetWare clients to access a Windows 2000 server
LastUpdated
P. Kyser TCM343

57. Planning Tip
If you upgrade NetWare servers to version 5.x or higher, convert from IPX/SPX to TCP/IP for better network communication options and better compatibility with Windows 2000 servers
LastUpdated
P. Kyser TCM343

58. MS NetBIOS A Communications Protocol
Network Basic IO System
Not recommended over TCP/IP
A combination software interface and network naming convention
Object named on the network
Available in Windows 2000 through the files Netbt.sys, NetBIOS.sys, and NetBIOS.dll
LastUpdated
P. Kyser TCM343

59. NetBEUI A Communications Protocol
NetBIOS Extended User Interface (NetBEUI): A non-routable communications protocol native to early Microsoft network communications
LastUpdated
P. Kyser TCM343

60. When to Use NetBEUI
For temporary backward compatibility when converting from Windows NT Server to Windows 2000 Server
For small networks that do not have Internet access, that do not use the Active Directory, that do not use routing, and that require only a basic installation
For backward compatibility with particular applications
LastUpdated
P. Kyser TCM343

61. DLC
Data Link Control (DLC) protocol: Enables communication with older IBM mainframes and minicomputers, and with some older HP print server cards
LastUpdated
P. Kyser TCM343

62. When to Use DLC
To connect to IBM and other computers that use Systems Network Architecture (SNA) communications
To connect to older peripheral devices, such as printers that use DLC
LastUpdated
P. Kyser TCM343

63. AppleTalk
AppleTalk: A peer-to-peer protocol used in network communication between Macintosh computers
Windows 2000 Server Services for Macintosh include:
File Server for Macintosh (MacFile)
Print Server for Macintosh (MacPrint)
AppleTalk protocol
LastUpdated
P. Kyser TCM343

64. When to Use AppleTalk
Use AppleTalk to enable Macintosh clients to connect to Windows 2000 Server
LastUpdated
P. Kyser TCM343

65. Binding Order
Windows NT and Windows 2000 enable you to set a binding order which establishes the protocol that will be tried first in a network communication (or a communication with a network printer)
E.g. Set TCP/IP to be first protocol tried to communicate with server, then IPX/SPX
LastUpdated
P. Kyser TCM343

66. Troubleshooting Tip
If network performance is slow and your network uses a combination of protocols, tune the binding order on Windows NT and Windows 2000 clients which can be an inexpensive way to immediately relieve network congestion
LastUpdated
P. Kyser TCM343

67. Network Planning Considerations
Size and purpose of the organization
Potential growth
Proportion of mission-critical applications
Role of the network to the mission of the organization
Security needs
Budget
Internet and intranet requirements
Interconnectivity requirements
LastUpdated
P. Kyser TCM343

68. Planning Tip Begin network planning by understanding: User needs
Important business processes
Current resources
Potential growth
LastUpdated
P. Kyser TCM343

69. Considerations in Selecting the Right Protocol(s)
Routing needs
Size of the network in terms of connections
Presence of Windows 2000 servers
Presence of mainframes and other computers that use SNA
Presence of NetWare servers
Access to the Internet or intranets
Presence of mission-critical and multimedia applications
LastUpdated
P. Kyser TCM343

70. Chapter Summary
Protocols are the life blood of a network, thus plan their use carefully.
The Microsoft NDIS driver enables using one or more protocols such as TCP/IP, IPX/SPX, NetBEUI, DLC, and AppleTalk.
For modern networking TCP/IP implementations are preferred.
LastUpdated
P. Kyser TCM343

71. Chapter Summary Plan to use only the protocols necessary.
Tune network binding order in Windows NT and Windows 2000 operating systems to enhance network performance.
LastUpdated
P. Kyser TCM343

72. LastUpdated 20040321 P. Kyser TCM343
Address Resolution Protocol (ARP) – A protocol in the TCP/IP suite that enables a sending station to determine the MAC address of another station on a network.
AppleTalk – A peer-to-peer protocol used in network communication between Macintosh computers.
bridge – A network transmission device that connects together different LAN segments using the same access method, for example connecting an Ethernet LAN to another Ethernet LAN or a token ring LAN to another token ring LAN. Bridge devices look at MAC addresses (OSI Layer 2) but do not look at routing information (Layer 3) in a frame.
connectionless communication – Also called a connectionless service, a communication service that provides no checks (or minimal checks) to make sure that data accurately reaches the destination node.
connection-oriented communication – Also called a connection-oriented service, this service provides several ways to ensure that data is successfully received at the destination, such as requiring an acknowledgement of receipt and using a checksum to make sure the packet or frame contents are accurate.
Data Link Control protocol (DLC) – Available through Microsoft Windows 2000, Windows NT, Windows 95, and Windows 98, this protocol enables communications with an IBM mainframe or minicomputer.
device address — Same as physical address.
Domain Name Service (DNS) – A TCP/IP application protocol that resolves domain and computer names to IP addresses; or IP addresses to domain and computer names.
dotted decimal notation – An addressing technique that uses four octets, such as , converted to decimal (e.g., ), to differentiate individual servers, workstations, and other network devices.
dynamic addressing – An addressing method where an IP (Internet Protocol) address is assigned to a workstation without the need for the network administrator to manually set it up at a workstation.
Dynamic Host Configuration Protocol (DHCP) – A network protocol that provides a way for a server to automatically assign an IP address to a workstation on its network.
enterprise network – A network that often reaches throughout a large area, such as a college campus, a city, or across several states. The main distinguishing factor of an enterprise network is that it brings together an array of network resources such as many kinds of servers, mainframes, intranets, printers, and the Internet.
Ethernet – A network transport system that uses a carrier sensing and collision detection method to regulate data transmissions.
File Transfer Protocol (FTP) – Available through the TCP/IP protocol, FTP enables files to be transferred across a network or the Internet between computers or servers.
LastUpdated
P. Kyser TCM343

73. KeyTerms LastUpdated 20040321 P. Kyser TCM343
frame – A unit of data that is transmitted on a network that contains control and address information, but not routing information.
Hypertext Transfer Protocol (HTTP) – A protocol in the TCP/IP suite that transports HTML documents over the Internet (and through intranets) for access by Web compliant browsers.
Internet Control Message Protocol (ICMP) – A TCP/IP-based protocol that is used for network error reporting, particularly through routing devices.
Internet Group Management Protocol (IGMP) – Part of the TCP/IP protocol suite, the protocol that is used in multicasting and which contains addresses of clients. It is used by the server to tell a router which clients belong to the multicast group.
Internet Packet Exchange (IPX) — A protocol developed by Novell for use with its NetWare server operating system (see Sequence Packet Exchange).
local area network (LAN) – A series of interconnected computers, printers, and other computer equipment that share hardware and software resources. The service area is usually limited to a given floor, office area, or building.
media access control (MAC) sublayer – A network communications function that examines physical address information in frames and controls the way devices share communications on a network
metropolitan area network (MAN) – A network that links multiple LANs within a large city or metropolitan region.
NetBIOS Extended User Interface (NetBEUI) – A communication protocol native to Microsoft network communications. It is an enhancement of NetBIOS, which was developed for network peer-to-peer communications among workstations with Microsoft operating systems installed on a local area network.
NetWare Link (NWLink) – A network protocol that simulates the IPX/SPX protocol for Microsoft Windows 95, Windows 98, Windows NT, and Windows 2000 communications with Novell NetWare file servers and compatible devices.
Network Basic Input/Output System (NetBIOS) – A combination software interface and a network naming convention. It is available in Microsoft operation systems through the file, NetBIOS.dll.
network binding – A process that links a computer’s network interface card or a dial-up connection with one or more network protocols to achieve optimum communications with network services. For Microsoft operating systems, you should always bind a protocol to each NIC that is installed.
Network Device Interface Specification (NDIS) – A set of standards developed by Microsoft for network drivers that enables communication between a NIC and a protocol; and that enables the use of multiple protocols on the same network.
Open Datalink Interface (ODI) — A driver that is used by Novell NetWare networks to transport multiple protocols on the same network.
Open Shortest Path First (OSFP) protocol – A TCP/IP-based routing protocol that can evaluate network paths and match a type of transmission, such as data or video, to the appropriate network path.
packet – A unit of data that is transmitted on a network that contains control and address information as well routing information.
physical address – Also called a device address, a unique hexadecimal number associated with a device’s network interface card.
protocol – A strictly defined set of rules for communication across a network that specifies how networked data is formatted for transmission, how it is transmitted, and how it is interpreted at the receiving end.
LastUpdated
P. Kyser TCM343

74. Key Terms LastUpdated 20040321 P. Kyser TCM343
Quality of Service (QoS) – Mechanisms used to measure and allocate network resources on the basis of transmission speed, quality, throughput, and reliability.
Resource Reservation Protocol (RSVP) – Enables an application to reserve the network resources it needs, such as network paths with higher speeds.
router – A device that connects networks, that can read IP addresses, and that can route packets to designated networks because it reads routing information in packets (Layer 3) and keeps tables of information about the fastest route from one network to another.
Routing Information Protocol (RIP) – A TCP/IP-based protocol that enables routing devices to share information about a network.
Sequence Packet Exchange (SPX) — A Novell connection-oriented protocol used for network transport when there is a particular need for data reliability (see Internet Packet Exchange).
Simple Mail Transfer Protocol (SMTP) – An protocol used by systems having TCP/IP network communications.
Simple Network Management Protocol (SNMP) – A TCP/IP-based protocol that enables servers, workstations, and network devices to gather standardized data about network performance and identify problems.
static addressing – An IP (Internet Protocol) addressing method that requires the network administrator to manually assign and set up a unique network address on each workstation connected to a network.
subnet mask – A designated portion of an IP address that is used to indicate the class of addressing on a network and to divide a network into subnetworks as a way to control traffic and enforce security.
Telnet – A TCP/IP application protocol that provides terminal emulation services.
token ring – Using a ring topology, a network transport method that passes a token from node to node. The token is used to coordinate transmission of data, because only the node possessing the token can send data.
topology – The physical layout of the cable and the logical path followed by network packets and frames sent on the cable.
Transmission Control Protocol/Internet Protocol (TCP/IP) – A protocol that is particularly well suited for medium and large networks. The TCP portion was originally developed to ensure reliable connections on government, military, and educational networks. It performs extensive error checking to ensure data is delivered successfully. The IP portion consists of rules for packaging data and ensuring it reaches the correct destination address.
User Datagram Protocol (UDP) – A protocol used with IP as an alternative to TCP and that offers low-overhead connectionless communications.
wide area network (WAN) – A far reaching system of networks that can extend across state lines and across continents.
Windows Internet Naming Service (WINS) – A Windows 2000 Server service that enables the server to convert NetBIOS workstation names to IP addresses for Internet communications.
LastUpdated
P. Kyser TCM343