How IP/ATM works

  • Article

Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2

How IP/ATM works

The three general stages of IP/ATM operation are:

  • Client initialization

  • Client registration

  • Data transfer

IP/ATM client startup and registration with a static IP address

The following example describes each step in establishing an IP/ATM connection for a single IP/ATM client with a static IP address:

Client registration

  1. Client A initializes and gets an ATM address from the ATM switch.

  2. Client A connects to the ATM ARP/MARS server and joins the broadcast group. Client A's IP-to-ATM address mapping is added to the ATM ARP server database.

  3. Client A contacts Client B, an ATM end station connected to the network, and begins data transfer.

IP/ATM client startup and registration with DHCP

The following example describes each step in establishing an IP/ATM connection for a single IP/ATM client obtaining an IP address using Dynamic Host Configuration Protocol (DHCP):

  1. The client initializes and gets an ATM address from the ATM switch.

  2. The client connects to the ATM ARP/MARS server and joins the broadcast group.

  3. The client connects to the multicast server and sends a DHCP request. The multicast server broadcasts the DHCP request to all members of the broadcast group. The DHCP server receives the request.

  4. The DHCP server sends a DHCP reply to the multicast server, which then broadcasts the reply to the broadcast group.

  5. The client receives the DHCP reply and then registers its IP and ATM addresses with the ATM ARP/MARS server.

  6. The client is now ready to contact other hosts and begin data transfer.

Note

  • For more information about DHCP, see DHCP.

Broadcasting and multicasting

A broadcast or multicast is used to establish point-to-multipoint connections between the requesting client and multiple end stations on the network. The process of broadcasting and multicasting on IP/ATM can follow two different methods:

  • Direct point-to-multipoint connection

    If a client needs to send an IP packet to a broadcast or multicast IP address, it sends a request to the MARS to resolve the IP address to a list of clients. The MARS sends a group of addresses to a client, allowing it to set up a point-to-multipoint connection.

  • Point-to-multipoint connection through a multicast server

    The MARS can also work with a multicast server. The Windows ATM ARP/MARS has an integrated multicast server, which registers one or more multicast groups with the MARS and receives a list of members in each multicast group from the MARS. The MARS updates the multicast server when clients join or leave a multicast group. When a client makes a multicast or broadcast request to the MARS, the MARS returns only the address of the multicast server. The client contacts the multicast server, which creates a point-to-multipoint connection with the multicast group. The multicast server copies and distributes the packets sent by the client that initiated the point-to-multipoint call to end stations on the multicast list.