RTS RVON-1, RVON-8, RVON-I, RVON-I/O Resource Manual
RVON Resource Guide
RVON-8
RVON-1
RVON-I/O
CHAPTER 1
Basic Network Configuration
Basic Network Configuration
This section covers basic network configuration set-up and testing. Also covered are basic concepts and
operations, including the difference between LAN and WAN networks and how IP Addressing is used.
In a networked environment, such as a company, typically there are many computers connected together using a
router or a switch. In larger companies, there may be several different routers distributed in buildings and plant
locations. A router allows any LAN-side computer to communicate with other computers and devices outside the
LAN (local area network). Routers send data packets from one place to another place on a network. routers use
network addresses to route packets to the correct destination. For example, in a TCP/IP network, the IP (internet
protocol) address of the network interface is used to direct router destinations.
Because routers help computers inside the LAN “talk” with computers outside of the LAN, the security of a
company’s LAN may be compromised by gaps of open ports in the router. Security measures may have been
instituted to compensate for these vulnerabilities. Consult you network administrator to learn about the security
measures taken to protect your network. VPN, or virtual private network, is one such security measure to protect
the intelligence of the LAN. A computer outside the LAN must have an address or key known by the VPN to
allow access to the LAN. Many companies use a VPN to connect two different LANs, thus allowing the transfer
of data between two networks.
LAN (local area network) vs. WAN (wide area network)
LOCAL AREA NETWORK
Simply put, a LAN is a computer network that connects a relatively small area (a single building or group of
buildings). Most LANs connect workstations and computers to each other. Each computer (also known as a
3
Basic Network Configuration
“node”), has its own processing unit and executes its own programs; however, it can also access data and devices
anywhere on the LAN. This means many users can access and share the same information and devices. A good
example of a LAN device is a network printer. Most companies cannot afford the budgetary or hardware expense
of providing printers for each of its users; therefore, one printer (or device) is placed on the LAN where every
user can access the same printer.
The LAN uses IP Addresses to route data to different destinations on the network. An IP Address is a 32-bit
numeric address consisting of four numbers separated by periods (for example, 1.160.10.240).
NOTE: For more information on IP Addresses, see you local network administrator.
Figure 1. Local Area Network Diagram
4
Basic Network Configuration
WIDE AREA NETWORK
A wide area network (WAN) connects two or more LANs and can span a relatively large geographical area. For
example, Telex Headquarters in Burnsville, MN is connected to several branch offices in Nebraska and
Arkansas over a WAN. The largest WAN in existence is the Internet.
Figure 2. Wide Area Network Diagram
ACCESSING THE WIDE AREA NETWORK (WAN)
Figure 3 shows LAN IP Addresses using a common IP Address, 10.2.100.X (192.168.X.X is another common
address). Most devices are shipped with these addresses as its default. It is recommended to use these addresses
for LANs.
Figure 3. Network Address Translation
5
Basic Network Configuration
NETWORK ADDRESS TRANSLATION (NAT)
Using the initial IP Address, then converting it to a valid WAN IP Address is how the network address translation
works, in theory. Once the IP address is changed, it is up to the network interface device (such as a router,
gateway, switch, etc.) to keep track of which computers are talking on which ports. For example, if two local
devices (PC1 and PC2 in Figure 3) both wanted to talk via port 1031, then the network interface device would
have to change one of the port requests to the next available port, 1032.
PORTS
In general, a network port is an endpoint to a logical connection. The port number identifies what type of port it
is. For example, port 80 is used for HTTP traffic. When you type an address into the address bar of a web
browser, your computer goes to find an IP Address for the url you are requesting (http://www.telex.com). To
obtain this address, the computer contacts a DNS server (Domain Name Server). Once the IP Address is found, it
tries to connect to the http port of the network device (port 80). See Table 1 for a list of the more well-known port
numbers.
Each network device can be set-up to respond or not respond to the various ports. The function of responding or
“hosting a service” is called “serving”.
TABLE 1. Packet Translation
Packet before Translation Packet after Translation
Source Destination Source Destination
To
Internet
From
Internet
IP Address
10.2.100.2 1031 192.156.136.22 80 99.5.1.30 1031 192.156.136.22 80
192.156.136.22 80 99.5.1.30 1031 192.156.136.22 80 10.2.100.2 1031
Port
Number
IP Address
Port
Number
IP Address
Port
Number
IP Address
Port
Number
If a second workstation on the LAN wants to communicate to the same server, and happens to use the same
source port number, then the LAN Modem will translate the source port number as well as the source IP address.
In Table, 2, a second LAN computer wants to access a web page. The NAT device now uses port 1032 for this
connection where it used port 1031 in Table 1.
6
Basic Network Configuration
TABLE 2. Packet Translation
Packet before Translation Packet After Translation
Source Destination Source Destination
To
Internet
From
Internet
IP Address
10.2.100.1 1031 192.156.136.22 80 99.5.1.30 1032 192.156.136.22 80
192.156.136.22 80 99.5.1.30 1032 192.156.136.22 80 10.2.100.1 1031
Port
Number
IP Address
Port
Number
IP Address
Port
Number
IP Address
Port
Number
Amazingly, all the address translation that occurs takes place automatically in order to make web browsing and
other functions easier. This is also a way for large web hosting services to speed up the network by having
different devices perform different functions.
7
Basic Network Configuration
TABL E 3. Well-Known TCP Port Numbers
TABLE 3. Well-Known TCP Port Numbers
Port
Number Description
1 TCP Port Service Multiplexer (TCPMUX)
5 Remote Job Entry (RJE)
7ECHO
18 Message Send Protocol (MSP)
20 FTP-Data
21 FTP- Control
23 Telnet
25 Simple Mail Transfer Protocol (SMTP)
29 MSG ICP
37 Time
42 Host Name Server (Nameserv)
43 Whols
49 Login Host Protocol (Login)
53 Domain Name Server (DNS)
69 Trivial File Transfer Protocol (TFTP)
70 Gopher Service
79 Finger
80 HTTP
103 X.400 Standard
108 SNA Gateway Access Server
109 POP2
110 POP3
Port
Number Description
115 Simple File Transfer Protocol
118 SQL Services
119 Newsgroup (NNTP)
137 NetBIOS Name Service
139 NetBIOS Datagram Service
143 Interim Mail Access Protocol (IMAP)
150 NetBIOS Session Service
156 SQL Server
161 SNMP
179 Border Gateway Protocol (BGP)
190 Gateway Access Control Protocol (GACP)
194 Internet Relay Chat (IRC)
197 Directory Location Services (DLS)
389 Lightweight Directory Access Protocol (LDAP)
396 Novell Netware over IP
443 HTTPS
444 Simple Network Paging Protocol (SNPP)
445 Microsoft-DS
458 Apple Quick Time
546 DHCP Client
547 DHCP Server
563 SNEWS
569 MSN
1080 Socks
8
Basic Network Configuration
IP ADDRESSES
If you do not know your IP Address, you can open a DOS screen in a Windows®- based environment and bring
up the ipconfig screen.
To find your IP Address using ipconfig, do the following:
1. From the Start Menu, open a Command Prompt screen.
2. At the prompt, type ipconfig, then press Enter.
The IP configurations appear for your machine, such as the DNS suffix, IP Address, Subnet Mask, and
Default Gateway.
3. At the prompt, type Exit to close the screen.
NOTE: If you want more detailed parameters for your machine, type ipconfig/All. This screen shows the
computers network configuration settings.
9
Basic Network Configuration
Ping a Computer
Pinging a computer on the network makes sure it is able to be “seen” and receive messages on the network.
NOTE: You can also ping your RVON-8 card to verify that it is responding over the network by putting the cards
IP Address in place of the computer IP Address.
To Ping a computer on the network, do the following:
1. From the Start menu, select Run... .
2. At the Run command, type CMD to open a Command Prompt screen.
3. At the prompt, type the IP Address of the computer you wish to ping (for example, 10.2.100.130).
4. Press Enter.
10
Basic Network Configuration
NOTE: If the computer you are pinging is not responding to the ping, you will receive a time-out message in the
command prompt screen.
POSSIBLE PITFALL WITH ROUTERS, GATEWAYS, AND SWITCHES
Anytime computers communicate through routers, gateways, and switches, they may be allowed or denied the
connection. Network interface devices can be configured to block specific outgoing requests, as well as
incoming requests, based on the IP Address and/or port. This is one of the security mechanisms of a router. This
also happens when broadcast messages are sent and received.
To view the path an IP Address takes to retrieve information, you can execute a tracert from the Command
Prompt Screen.
1. From the Start Menu, open a Command Prompt screen.
2. At the prompt, type tracert and type the url or IP Address you want to trace.
3. Press Enter.
The details of the tracer route are displayed.
11
Basic Network Configuration
NOTE: You will the message “request timed out” if the IP Address/ port IN or OUT is denied to the incoming or
outgoing message.
4. When you are finished, type exit to close the Command Prompt screen.
RVON Configuration
RVON cards use ports for communication of audio and control packets. Because routers can be configured to
block certain incoming and outgoing requests, you will need to open the following ports in your network to allow
WAN connections to and from a Network Interface Device. See Table X for the ports that need to be opened for
the RVON cards to operate properly.
TABLE 4. Ports necessary for RVON card functionality.
Port Port Description
2076 UDP Call Control Signalling
2077 UDP Audio Packets
2079 UDP Telex Proprietary Signalling
2080 TCP Telex Keypanel Protocol
2081 UDP Pass Through Serial
2082 TCP Firmware Download
2100 Remote Administration
2102 Authentication Server
12
Network Terminology
Figure X is an example of a router configuration screen. Not all routers are configured the same way and may
not look exactly like this screen.
NOTE: Linksys™ supports up to 253 nodes on a router. This is why it is called a Router/Switch because there
are WAN functions like a router as well as having a 4-port LAN switch. It also does not support simultaneous
forward and DHCP.
Network Terminology
Bridges
A bridge is a device that connects two LANs, or two segments of the same LAN that use the
same protocol. Sometimes called “transparent bridges, they work at the OSI model Layer 2.
Simply put, they are not concerned with protocols. Their main job is to pass data to a
destination address that is predetermined in the data packet.
With a bridge, all of your computers are on the same network subnet (see Subnet). This means
your computers can communicate with each other and have their own Internet connection. If
you assign your own IP Addresses be sure to use the same first 3 “octets” of the IP Address
(for example, 192.168.0.X).
13
Basic Network Configuration
Domain Name Server (DNS)
A DNS Server is an Internet service that translates domain names (for example, in the URL
http://www.telex.com, the domain name is the telex.com) into IP Addresses. The Internet is
based on IP Addresses which are numeric and since domain names are alphabetic, they are
easier to remember. Every time a domain name is used it must go through the DNS server to be
translated into an IP Address.
Gateway
A gateway is a node on a network that serves as an entrance to another network. The gateway
routes traffic from a computer to an outside network that is serving the web pages. For
example, the gateway for a home computer is the ISP provider that connects the user to the
Internet.
In a corporate environment, the gateway often acts as a proxy server and a firewall. Gateways
are similar to routers and switches in that they forward data to the destination and provide the
path for which the data will travel to the destination.
Hub
A hub is a common connection point for devices in a network. A hub has multiple ports. When a
data packet arrives at a hub, it is copied and distributed to all of its ports so that all nodes on the
LAN can see the packets.
There are three types of hubs:
passive hub
- this hub serves as a conduit for the data, enabling it to go from one device to another.
intelligent hub (also known as manageable hubs) - this hub includes addition features that enable
administrators to monitor traffic through the hub.
switching hub - this hub reads the destination address of each packet and then forwards the data
pack to the appropriate port.
IP Address (Internet Protocol Address)
An IP Address is an identifier or numerical name for a computer or device on a network. Data
between computers are routed over the network using these addresses to identify the computer
the message is being sent to and the computer the message is being sent from.
The format of an IP Address is a 32-bit numeric address written as four numbers separated by
periods. For example, an IP Address looks like 10.100.1.1.
IMPORTANT: When working within an isolated network (meaning there is no Internet
access), IP Addresses can be assigned at random just as long as they are unique to each
computer and device. When the isolated network is connected to the Internet, registered
Internet Addresses must be obtained. This is to prevent duplication of addresses.
14
Network Terminology
The four numbers in and IP Address are used in different was to identify a particular network
and host on that network. There are three classes of Internet Addresses.
CLASS A - supports 16 million hosts on each of 127 networks.
CLASS B - supports 65,000 hosts on each of 16,000 networks.
CLASS C - supports 254 hosts on each of 2 million networks.
LAN
A LAN is a computer network that connects a relatively small area (a single building or group
of buildings). Most LANs connect work stations and computers to each other. Each computer
(also known as a “node”), has its own processing unit and executes its own processing unit and
executes its own programs; however it can also access data and devices anywhere on the LAN.
This means that many users can access and share the same information and devices. A good
example of a LAN device is a network printer. Most companies cannot afford the budgetary or
hardware expense of providing printers for each of its users; therefore, one printer (i.e., device)
is placed on the LAN where every user can access the same printer.
The LAN uses IP Addresses to route data to different destinations on the network. An IP
Address is a 32-bit numeric address written as four numbers separated by periods (for example
1.160.10.240).
Port
A port, when referring to TCP and UDP networks, is an endpoint in a logical connection. The
port number identifies the type of port it is. For example, port 80 is used for HTTP traffic.
15
Loading...