ipdcm(7M) (man pages section 7: Device and Network Interfaces)

man pages section 7: Device and Network Interfaces

ipdcm(7M)

NAME | DESCRIPTION | FILES | ATTRIBUTES | SEE ALSO

NAME

ppp, ppp_diag, ipd, ipdptp, ipdcm– STREAMS modules and drivers for the Point-to-Point Protocol

DESCRIPTION

Note –

ppp has been superseded and may be removed from future versions of Solaris. Refer to pppd(1M) instead. See /etc/ppp/ for configuration files. Use man pppd for more information.

ppp is a STREAMS module which implements the Point to Point Protocol (“PPP”). PPP is a datalink protocol which provides a method for transmitting datagrams over serial point-to-point links. PPP allows for various options to be negotiated between the two hosts of a point-to-point link; these options provide things such as peer authentication, header compression, link quality monitoring, and mapping of control characters. The PPP specifications are described in RFC 1331, The Point-to-Point Protocol for the Transmission of Multi-protocol Datagrams over Point-to-Point Links and RFC 1332, The PPP Internet Protocol Control Protocol (IPCP).

The pseudo device drivers /dev/ipd, /dev/ipdptp, and /dev/ipdcm form the IP-dialup layer. This layer provides IP network interfaces for dialup (connect on demand) point-to-point links. The ipd and ipdptp devices are the IP-dialup network interfaces. The ipd device provides a point-to-multipoint interface, and the ipdptp device provides a point-to-point interface. The ipdcm device supplies an interface between the ipd or ipdptp device and a link manager.

The ppp module and IP-dialup layer work together to provide IP connectivity over serial point-to-point links. A "link manager" daemon is responsible for setting up and tearing down these dialup connections. Connections are established when an IP packet needs to be sent to the remote host, or the remote host has indicated its desire to establish a PPP connection.

The ppp_diag module captures PPP layer packets and parses the contents for debugging purposes. Usually, the parsed output is sent to the strlog facility from which it is retrieved by the link manager. This module is pushed between the serial device and the ppp module by the link manager when debugging is enabled.

Operation

When a packet is routed to an IP-dialup point-to-point interface which is not currently connected to the remote host, the ipdcm driver sends a message to the link manager to establish the connection. The link manager opens a communications channel and pushes the ppp module onto the corresponding serial device. The ppp module negotiates with the remote host on which options will be used for the link. When both hosts have agreed on a set of options, the link manager links the ppp module and serial device underneath the ipd or ipdptp interface which is providing the IP interface to the remote host.

Similarly, a remote host may initiate a connection on an enabled communications port. In this case the link manager receives the request and pushes the ppp module onto the corresponding device. Once the ppp module has successfully negotiated on the set of options for the link with its peer, the link manager links the ppp module and serial device underneath the ipd or ipdptp interface which is providing the IP-dialup interface.

When the ppp module and serial device have been linked underneath the IP-dialup interface, IP packets are sent and received over the point-to-point link in PPP frames.

FILES

/dev/ipd: pseudo device driver that provides point-to-ipoint interface.
/dev/ipdptp: pseudo device driver that provides point-to-multipoint interface.
/dev/ipdcm: pseudo device driver that provides interface between ipd and ipdptp and link manager.

ATTRIBUTES

See attributes(5) for descriptions of the following attributes:

`ATTRIBUTE TYPE`	`ATTRIBUTE VALUE`
Availability	SUNWpppk