IBM 9077 ユーザーズマニュアル

Configuration of IP-Forwarding Media Cards 

  • VC-Based Multiplexing (RFC 1483, section 5)

When LLC Encapsulation is used, a single PVC is configured to carry 

all

 

bridged traffic. The same PVC can also carry nonbridged traffic such as 
routed IP datagrams.

When VC-Based Multiplexing is used, multiple PVCs are defined for the 
logical interface. Each PVC carries a 

specific

 type of traffic. For example, one 

PVC carries Ethernet while another carries FDDI.

The next three steps describe ATM bridging configuration requirements and 
options. Examples of configured PVCs follow.

1. In the Traffic Shaping section of the /etc/gratm.conf file, set traffic shaping 

name and quality of service (qos) parameters. Choose a name of your 
choice for each type of service that will be assigned:

# Traffic shaping parameters

# Lines beginning with the keyword "Traffic_Shape" define

# traffic shapes which may be used to configure the performance

# characteristics of ATM Virtual Circuits.

#

Traffic_Shape name=myown_high_speed_high_quality \

peak=155000 sustain=155000 burst=2048 qos=high

2. To configure a logical interface for bridging, you create an Interface entry 

in the Interface section of the /etc/gratm.conf file. This entry must include 
the intended bridging method. Specify it with the bridge_method= 
keyword. 

Here is a sample Interface entry:

Interface ga030 traffic_shape=myown_high_speed_high_quality \

bridge_method=vc_multiplexed

There are two types of bridging methods to specify:

  • VC-Based Multiplexing, bridge_method=vc_multiplexed

The configuration must include one or more PVCs for this interface 
specified in the PVC section and defined with proto=vcmux_bridge.

  • LLC Encapsulation, bridge_method=llc_encapsulated

The configuration must include one PVC for this interface specified in 
the PVC section and defined with proto=llc,bridging. Media and 
transmission restrictions can also be specified with this keyword.

3. One or more PVCs must be defined in the PVC section for each logical 

interface specified for bridging in the Interface section.