| STRIP(4) | Device Drivers Manual | STRIP(4) | 
strip —
pseudo-device strip
strip driver takes outbound network packets,
  encapsulates them using the Metricom “star mode” framing, and
  sends the packets out an RS-232 interface to a Metricom
  Ricochet packet radio. Packets arriving from the packet
  radio via the serial link are decapsulated and then passed up to the local
  host's networking stack.
strip is an acronym for
    STarmode Radio IP.
The strip interfaces can be created by
    using the ifconfig(8)
    create command. Each strip
    interface is a pseudo-device driver for the Metricom
    Ricochet packet radio, operating in peer-to-peer packet
    mode.
In many ways, the strip driver is very
    much like the sl(4) SLIP
    pseudo-device driver. A strip device is attached to
    a tty line with slattach(8).
    Once attached, the interface is configured via
    ifconfig(8). The major
    difference between the sl(4) SLIP
    pseudo-device driver and the strip driver is that
    SLIP works only between two hosts over a dedicated point-to-point
    connection.
In contrast, strip sends packets to a
    frequency-hopping packet radio, which can address packets to any peer
    Metricom Ricochet packet radio, rather than just to a
    single host at the other end of a point-to-point line. Thus, one
    strip pseudo-device is usually sufficient for any
    kernel.
In other respects, a strip interface is
    rather like an Ethernet interface. Packets are individually addressed, and
    subsequent packets can be sent independently to different MAC addresses.
    However, the “star mode” framing and MAC addressing are not in
    any way compatible with Ethernet. Broadcast or multicast to more than one
    packet radio is not possible, due to the independent frequency-hopping
    operation of the packet radios. The interface flags
    IFF_POINTOPOINT and
    IFF_BROADCAST are not supported on the
    strip interface.
In other words, strip implements a
    multiple-access, non-broadcast device, accessed via an RS-232 serial line,
    using a proprietary packet framing scheme.
This version of the strip driver maps IP
    addresses to Metricom Ricochet packet radio addresses
    using statically configured entries in the normal routing table. These
    entries map IP addresses of peer packet radios to the MAC-level addresses.
    The exact syntax of this mapping and an example are discussed below. The
    Internet Assigned Numbers Authority (IANA) has allocated an ARP type code
    for use with STRIP. A future version of this driver will support
    arp(4) to obtain the IP address
    of reachable peer packet radios dynamically.
Radio addresses are encoded using the hex equivalent of the packet radio's decimal ASCII address. For example, the following route command will configure a routing entry to a packet radio with a MAC address of 1234-5678, and an IP address 10.11.12.13, reachable via the strip0 interface:
route add -host 10.11.12.13 -link strip0:1:2:3:4:5:6:7:8
Generalising from this example to other IP addresses and to other 8-digit MAC addresses should be clear.
ATS304=115200 to set
  the serial baudrate to the specified number (or 0 for autobaud). The command
  AT&W will then save the current packet radio state
  in non-volatile memory.
Metricom Ricochet packet radios can operate in
    either “modem-emulation” mode or in packet mode (i.e.
    “star mode”). The strip driver
    automatically detects if the packet radio has fallen out of “star
    mode”, and resets it back into “star mode”, if the baud
    rate was set correctly by
    slattach(8).
strip was originally developed for the Linux kernel by
  Stuart Cheshire of Stanford's Operating Systems and Networking group, as part
  of Mary Baker's MosquitoNet project.
This strip driver was ported to
    NetBSD by Jonathan Stone at Stanford's Distributed
    Systems Group and first distributed with NetBSD
  1.2.
strip is IP-only. Encapsulations for
  AppleTalk and ARP have been defined, but are not yet implemented in this
  driver.
strip has not been widely tested on a
    variety of lower-level serial drivers.
The detection and resetting of packet radios that crash out of
    “star mode” does not always work in this version of the
    driver. One workaround is to kill the
    slattach(8) process,
    ifconfig(8) the
    strip interface down, and then start a new slattach
    and rerun ifconfig to enable the interface again.
| December 5, 2004 | NetBSD 9.4 |