Translation Table on SONET/SDH OC48/STM16 IQE PICs
On the SONET/SDH OC48/STM16 IQE PIC, the behavior aggregate
(BA) translation tables are included for every logical
interface (unit) protocol family configured on the
logical interface. The proper default translation table is active
even if you do not include any explicit translation tables. You can
display the current translation table values with the show class-of-service translation-table
command.
On M320, MX series, T640, and T1600 routers with SONET/SDH OC48/STM16
IQE PICs, you can replace the type-of-service (ToS) or DSCP or MPLS
(EXP) bit value on the incoming packet header on a logical interface
with a user-defined value. The new value is used for all class-of-service
processing and is applied before any other class-of-service or firewall
treatment of the packet. On the SONET/SDH OC48/STM16 IQE PIC, the
values configured with the translation-table
statement
determines the new ToS bit values.
The SONET/SDH OC48/STM16 IQE PIC supports four types of translation tables: IP precedence, IPv4 DSCP, IPv6 DSCP, and MPLS (EXP). You can configure a maximum of eight tables for each supported type. If a translation table is enabled for a particular type of traffic, then BA classification of the same type must be configured for that logical interface. That is, if you configure an IPv4 translation table, you must configure IPv4 BA classification on the same logical interface.
You can define many translation tables, as long as they have
distinct names. You apply a translation table to a logical interface
at the [edit class-of-service interfaces]
hierarchy level.
Translation tables always translate “like to like.” For
example, a translation table applied to MPLS traffic can translate
only from received EXP bit values to new EXP bit values. That is,
translation tables cannot translate, for instance, from DSCP bits
to INET precedence code points.
With translation table, the original fields in the received packet are overwritten with the new values configured in the translation table and the old values will be lost.