NATMIP(4) | Device Drivers Manual | NATMIP(4) |
NAME¶
natmip — IP over ATM PVCsSYNOPSIS¶
device atmoptions NATM
DESCRIPTION¶
The NATM protocol stack includes support for IP over ATM. Without any additional signalling stacks or other modules it is possible to build a CLIP (classical IP over ATM) network based on PVCs. An ATM network card (en0
in this example) is configured
for IP by something like:
ifconfig en0 128.252.200.1 netmask 0xffffff00
up
- byte 0
- Is a flag byte. Currently only flag 0x20 is used. When set, all IP frames are LLC/SNAP encapsulated before putting them into an AAL5 frame. Setting this flag is recommended and allows interoperability with other CLIP implementations. Note that BPF works only with LLC/SNAP encapsulation.
- byte 1
- This is the VPI of the channel.
- bytes 2...3
- VCI of the channel. Must not be zero.
- byte 4
- Traffic type. One of 0 (UBR), 1 (CBR), 2 (ABR), 3 (VBR).
- bytes 5...7
- Specifies the peak cell rate for UBR.
- bytes 5...7
- Specifies the peak cell rate for CBR.
- bytes 5...7
- Specifies the peak cell rate for VBR.
- bytes 8...10
- This is the sustainable cell rate.
- bytes 11...13
- The maximum burst size.
- bytes 5...7
- Specifies the peak cell rate for ABR.
- bytes 8...10
- The minimum cell rate.
- bytes 11...13
- The initial cell rate.
- bytes 14...16
- The transient buffer exposure.
- byte 17
- The NRM value.
- byte 18
- The TRM value.
- bytes 19...20
- The ADTF value.
- byte 21
- The rate increase factor (RIF).
- byte 22
- The rate decrease factor (RDF).
- byte 23
- The cutoff decrease factor (CDF).
route
add -iface
⟨remote IP address⟩
-link
⟨iface⟩:⟨lladdr⟩
The iface is the ATM interface through which
remote IP address can be reached and
lladdr is the link layer address as a string of
dot-separated, hexadecimal bytes.
NATM also supports the old, original format. This consists of 4 byte link layer
addresses (and the channels are implicit UBR):
- byte 0
- Flags:
- 0x01
- use AAL5.
- 0x02
- if using AAL5, use an LLC/SNAP header.
- byte 1
- VPI for the channel
- bytes 2...3
- VCI for the channel
EXAMPLES¶
Suppose you have 3 hosts 128.252.200.1, 128.252.200.2 and 128.252.200.3 connected by ATM through PVCs:- between 128.252.200.1 and 128.252.200.2: 0xc9 UBR
- between 128.252.200.1 and 128.252.200.3: 0xca VBR
- between 128.252.200.2 and 128.252.200.3: 0xcb CBR
ifconfig en0 128.252.200.1 netmask 0xffffff00 up route add -iface 128.252.200.2 -link en0:3.0.0.c9.0 route add -iface 128.252.200.3 -link en0:3.0.0.ca.3.0.c3.50.0.27.10.0.0.a
ifconfig en0 128.252.200.2 netmask 0xffffff00 up route add -iface 128.252.200.1 -link en0:3.0.0.c9.0 route add -iface 128.252.200.3 -link en0:3.0.0.cb.1.1.86.a0
ifconfig en0 128.252.200.3 netmask 0xffffff00 up route add -iface 128.252.200.1 -link en0:3.0.0.ca.3.0.c3.50.0.27.10.0.0.a route add -iface 128.252.200.2 -link en0:3.0.0.cb.1.1.86.a0
network_interfaces="lo0 en0" ifconfig_en0="inet 128.252.200.1 netmask 255.255.255.0" static_routes="host2 host3" route_host2="-iface 128.252.200.2 -link en0:3.0.0.c9.0" route_host3="-iface 128.252.200.3 -link en0:3.0.0.ca.3.0.c3.50.0.27.10.0.0.a"
network_interfaces="lo0 en0" ifconfig_en0="inet 128.252.200.2 netmask 255.255.255.0" static_routes="host1 host3" route_host1="-iface 128.252.200.1 -link en0:3.0.0.c9.0" route_host3="-iface 128.252.200.3 -link en0:3.0.0.cb.1.1.86.a0"
network_interfaces="lo0 en0" ifconfig_en0="inet 128.252.200.3 netmask 255.255.255.0" static_routes="host1 host2" route_host1="-iface 128.252.200.1 -link en0:3.0.0.ca.3.0.c3.50.0.27.10.0.0.a" route_host2="-iface 128.252.200.2 -link en0:3.0.0.cb.1.1.86.a0"
SEE ALSO¶
en(4), fatm(4), hatm(4), natm(4), patm(4)AUTHORS¶
Chuck Cranor of Washington University implemented the NATM protocol layer along with the EN ATM driver in 1996 for NetBSD.August 11, 2003 | Debian |