This page is intended to give you an insight to setting up your Asymmetric Digital Subscriber Line internet connection. The settings outlined here are the ones we use and are only meant as a guide. Your ISP may have different settings
virtual connection settings
A Virtual Connection (VC) is a link that seems and behaves like a dedicated point-to-point line or a system that delivers packets in sequence, as happens on an actual point-to-point network. In reality, the data is delivered across a network via the most appropriate route. The sending and receiving devices do not have to be aware of the options and the route is chosen only when a message is sent. There is no pre-arrangement, so each virtual connection exists only for the duration of that one transmission.
| VC Setting | Value |
|---|---|
| Virtual Path Identifier (VPI). | 0 |
| Virtual Channel Identifier (VCI) | 38 |
| Asynchronous Transfer Mode (ATM) | UBR |
| MAC Spoofing | - |
| Encapsulation | PPPoA VC-Mux |
| Bridge | Disabled |
| Internet Group Management Protocol(IGMP) | Disabled |
| Maximum Receive Unit (MRU) | 0 |
| Maximum Transmission Unit (MTU) | 0 |
| Maximum Segment Size (MSS) | 0 |
VC settings
Virtual Path Identifier (VPI). 8-bit field in the header of an ATM cell.
Virtual Channel Identifier (VCI) 16-bit field in the header of an ATM cell.
The VCI, together with the VPI, is used to identify the next destination of a cell as it passes through a s series of ATM switches on its way to its destination.
data packets
The Maximum Receive Unit (MRU) is sent to inform the peer that the implementation can receive larger packets, or to request that the peer send smaller packets.
The Maximum Transmission Unit (MTU) is the largest packet that a given network medium can carry. Ethernet, for example, has a fixed MTU of 1500 bytes, ATM has a fixed MTU of 48 bytes, and PPP has a negotiated MTU that is usually between 500 and 2000 bytes.
The Maximum Segment Size (MSS) is the largest quantity of data that can be transmitted at one time.
PVC
Permanent Virtual Circuit (PVC): This is a link with static route defined in advance, usually by manual setup.
ATM
Asynchronous Transfer Mode; a high-speed packet-switching transport used for transmitting data over LANs or WANs that transmits fixed-length units of data. It provides any-to-any connectivity and nodes can transmit simultaneously.
Unspecified Bit Rate (UBR) a type of traffic that is not considered time-critical (e.g., ARP messages, pure data), allocated whatever bandwidth is available at any given time. UBR traffic is given a "best effort" priority in an ATM network with no guarantee of successful transmission
Constant Bit Rate (CBR) An ATM service category which supports a constant or guaranteed rate to transport services such as video or voice as well as circuit emulation which requires rigorous timing control and performance parameters.
protocols
Challenge Handshake Authentication Protocol (CHAP). A type of authentication protocol in which the authentication agent sends the client program a key to be used to encrypt the user name and password. CHAP doesn't only require the client to authenticate itself at startup time, but sends challenges at regular intervals to make sure the client hasn't been replaced by an intruder
Internet Group Management Protocol (IGMP) . Used by IP hosts to report their multicast group memberships to an adjacent multicast router.
Network Address Translation(NAT) - A program or piece of hardware that converts the IP address from a private address to a public address real time. This allows multiple users to share a single public IP address. It also prevents access to these users from the outside without special configurations. NAT is used in home networks and corporations to allow multiple PCs to access the internet via T-1, ADSL, SDSL or Cable Modem.
Point to Point Protocol (PPP) - The protocol that is used to connect to the internet and corporate networks via dialup networking. PPP depends on CHAP, PAP or scripts for authentication.
