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I have a "ADSL Modem Router with 4 Ethernet Port Switch" made by eTEC with Conexant software (firmware version "ETHADSL_USB_032002_REL9"). The manual didn't really explain anything so I've researched all the options myself:
Out of the box the router has a LAN IP address of 10.0.0.2, so entering "http://10.0.0.2" into a LAN side browser shows a screen such as:
Configuration - WAN
These settings enable me to connect to my ISP (BT).
DSL broadband ISP's such as BT use a technology called ATM. Asynchronous Transfer Mode (ATM) is the world's most widely deployed backbone technology. It can be viewed as an evolution of packet switching. Like packet switching for data (e.g., TCP/IP), ATM integrates the multiplexing and switching functions, is well suited for bursty traffic (in contrast to circuit switching), and allows communications between devices that operate with different bandwidth requirements. Unlike packet switching, ATM is designed for high-performance multimedia networking.
The most basic service building block is the ATM virtual circuit, which is an end-to-end connection that has defined end points and routes but does not have bandwidth dedicated to it. Bandwidth is allocated on demand by the network as users have traffic to transmit.
What is VPI and VCI? ATM is a connection orientated protocol and as such there is a connection identifier in every cell header which explicitly associates a cell with a given virtual channel on a physical link. The connection identifier consists of two sub-fields, the Virtual Channel Identifier (VCI) and the Virtual Path Identifier (VPI). Together they are used in multiplexing, demultiplexing and switching a cell through the network.
| Field | Setting | Comments |
|---|
Default
Gateway |
0.0.0.0 |
The default gateway is where you connect in order to reach the Internet. 0.0.0.0 means that the router will find the ISP's IP address automatically. |
Per VC settings: My router allows me to configure 8 ATM virtual circuits. I'll only need 1.
| General |
|
- Enabled? I enabled one virtual circuit (VPI 0). I don't need 8!
VPI: 0 - Virtual Channel Identifier (see above)
- VCI 38 - Virtual Path Identifier (see above)
- Static IP address: Your ISP will tell you this if you have a static IP number. For BT you have no static address, leave this blank.
- Subnet Mask: ditto.
|
| Mac Spoofing |
Disable |
This allows you to set the MAC address of the WAN interface on the gateway. Your can enable this to let your ISP think you only have one computer |
| ATM Service Category |
UBR |
UBR (unspecified bit rate) service class is intended for delay-tolerant traditional computer communication applications.
CBR (constant bit rate) service class is intended for real-time applications needing a specified constant bit rate. |
| Encapsulation |
PPPoA VC-Mux |
PPP(Point-to-Point Protocol) is the Internet Standard for transmission of IP packets over serial lines:
- PPPoA VC-Mux - Point-to-Point Protocol over ATM using VC multiplexing. VC-based multiplexing uses one Virtual Channel (VCI/VPI pair) for each protocol. See RFC 2364.
- PPPoA LLC - Point-to-Point Protocol over ATM using Logical Link Control encapsulation. See RFC 2364.
- 1483 Bridged IP LLC - Bridged IP over ATM using . See RFC 1483.
- 1483 Routed IP LLC - Routed IP over ATM using LLC. See RFC 1483.
- 1483 Bridged IP VC-Mux - Bridged IP over ATM using VC multiplexing. See RFC 1483.
- 1483 Routed IP VC-Mux - Routed IP over ATM using VC multiplexing. See RFC 1483.
- Classical IP over ATM - Classical IP over ATM. See RFC 1483.
- PPPoE VC-Mux - PPP over Ethernet using VC multiplexing. See RFC 2516.
- PPoE LLC - PPP over Ethernet using LLC. See RFC 2516.
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| Bridge |
Disabled |
Turn the router into a bridge between two ATM newtorks? |
| IGMP |
Disabled |
Internet Group Management Protocol: An extension to the Internet Protocol, used by IP hosts to multicast. Multicasting allows one computer on the Internet to send content to multiple other computers that have identified themselves as interested in receiving the originating computer's content. |
| PPP Configuration |
|
These setting depend on your ISP. BT only required you to fill in the username (tom.fotherby@btbroadband.com)
- Service Name
- Username: To test your connection use bt_test@startup_domain, with no password. You will then be able to go to www.bt.net/digitaldemo and watch a little video.
- Password
- Disconnect Timeout: 0
- Authentication: Auto
- Automatic Reconnect: BT say no, apparently.
|
| DHCP client enable |
Yes / No |
DCHP client: The router can use another DHCP server to assign IP addresses. |
Configuration - LAN
IP address
| 10.0.0.2
|
Assuming you are using the same addressing scheme as me. This must be a unique number on your LAN |
| Subnet Mask |
255.0.0.0 |
Any IP address beginning with 10 is a LAN computer |
| DHCP Server |
Yes | No |
If you are using static IP within your own LAN then you don't need a Dynamic Host Configuration Protocol server.
Otherwise a DCHP server can automatically assign IP addresses to LAN computers. |
| Ethernet Mode |
AutoSense |
|
Configuration - NAT (Network Address Translation)
This allows all the computers on your LAN to get out onto the internet, even though you only have one internet address. The great unwashed Internet only sees your router, not your whole network.
First add a session name by following the link to 'Session Name Configuration'. Call it what you like, I'll use 'foo'. Use virtual circuit 0. Go back to NAT configuration.
Set the first menu to 'NAPT' (Network Address and Port Translation) if you ever intend to use more than one PC on the LAN to access the internet. For 1 PC, NAT may work.
For each of the computers on your network, type 'foo' 'into 'session name' and the computers IP address into 'Users IP', click add. Submit the page before you leave.
Configuration - Virtual Server.
You only need this if you want to run a webserver. Virtual server is how you allow the outside world to initiate connections into your LAN. For example, if you want to run
a web server on your PC 10.0.0.5, make public port 80 and private port 80 (or whatever your server uses) and the Host IP Address 10.0.0.5. Do this for each port you want to allow hosts on the Internet to access.
Configuration - Bridge Filtering
Disable this.
Configuration - DNS
Your router can act as the DNS server for your network. It just queries the real DNS server and passes the results back to your network. To use your ISP's name-server select Use Autodiscovered Servers.
Route Table
| Destination | Netmask | Gateway | Interface | Explanation |
|---|
| 0.0.0.0 | 0.0.0.0 | 217.32.11.66 | ppp1 | WAN side Point-to-Point Protocol linking my default gateway of 0.0.0.0 to my ISP's IP of 217.32.11.66 |
| 10.0.0.0 | 255.0.0.0 | 10.0.0.2 | br0 | 10.0.0.2 is the gateway for LAN side machines. Traffic beginning with 10.X.X.X is kept inside the network whilst other traffic is bridged across the router to the internet |
| 127.0.0.1 | 255.0.0.0 | 127.0.0.1 | lo0 | loopback |
| 217.32.11.66 | 255.255.255.255 | 217.44.178.1 | ppp1 | I think this sets up a real gateway to my ISP that 0.0.0.0 actually uses |
Admin Privilege - ADSL Configuration
| Trellis |
Enabled |
| Handshake Protocol |
Autosense G.dmt first |
| Wiring Selection |
Tip/Ring |
| Bit Swapping |
Disabled |
Admin Privilege - RIP Configuration
Just disable Routing Information Protocol.
Admin Privilege - Misc Configuration
| WAN side HTTP server |
Disabled |
You almost certainly don't want to be able to admin the router from the Internet. It would be a perfect candidate for a automated password cracker program |
| FTP Server |
Disabled |
You only need the FTP server running when you want to upload new firmare. Possibly not even then. |
| TFTP server |
Disable |
The Trivial File Transfer Protocol (TFTP) enables you to transfer files to and from remote systems. For example to upload new firmware. |
| HTTP Server port |
8080 |
This is what the router admin server listens on. If the WAN side HTTP server is switched on, it shouldn't be the same port as any virtual server. |
| DMZ |
Disabled |
If you don't use a virtual server, you can use a De-Militerised Zone to forward all traffic on the WAN IP to your webserver. |
| DHCP Relay |
Disabled |
|
| IGMP Proxy |
Disabled |
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| PPP reconnect on WAN access |
Enabled |
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