For link services IQ (lsq) interfaces, you can specify fragmentation properties for specific forwarding classes. Traffic on each forwarding class can be either multilink encapsulated (fragmented and sequenced) or nonencapsulated (hashed with no fragmentation). By default, traffic in all forwarding classes is multilink encapsulated.
When you do not configure fragmentation properties for the queues on MLPPP interfaces, the fragmentation threshold you set at the [edit interfaces interface-name unit logical-unit-number fragment-threshold] hierarchy level is the fragmentation threshold for all forwarding classes within the MLPPP interface. For MLFR FRF.16 interfaces, the fragmentation threshold you set at the [edit interfaces interface-name mlfr-uni-nni-bundle-options fragment-threshold] hierarchy level is the fragmentation threshold for all forwarding classes within the MLFR FRF.16 interface.
If you do not set a maximum fragment size anywhere in the configuration, packets are still fragmented if they exceed the smallest maximum transmission unit (MTU) or maximum received reconstructed unit (MRRU) of all the links in the bundle. A nonencapsulated flow uses only one link. If the flow exceeds a single link, then the forwarding class must be multilink encapsulated, unless the packet size exceeds the MTU/MRRU.
Even if you do not set a maximum fragment size anywhere in the configuration, you can configure the MRRU by including the mrru statement at the [edit interfaces lsq-fpc/pic/port unit logical-unit-number] or [edit interfaces interface-name mlfr-uni-nni-bundle-options] hierarchy level. The MRRU is similar to the MTU, but is specific to link services interfaces. By default the MRRU size is 1500 bytes, and you can configure it to be from 1500 through 4500 bytes. For more information, see Configuring the MRRU and MTU Values.
To configure fragmentation properties on a queue, include the fragmentation-maps statement at the [edit class-of-service] hierarchy level:
- [edit class-of-service]
-
fragmentation-maps {
-
-
map-name {
-
-
forwarding-class class-name {
- (fragment-threshold bytes | no-fragmentation);
-
multilink-class number;
- }
- }
- }
To set a per-forwarding class fragmentation threshold, include the fragment-threshold statement in the fragmentation map. This statement sets the maximum size of each multilink fragment.
To set traffic on a queue to be nonencapsulated rather than multilink encapsulated, include the no-fragmentation statement in the fragmentation map. This statement specifies that an extra fragmentation header is not prepended to the packets received on this queue and that static link load balancing is used to ensure in-order packet delivery.
For a given forwarding class, you can include either the fragment-threshold or no-fragmentation statement; they are mutually exclusive.
You use the multilink-class statement to map a forwarding class into a multiclass MLPPP (MCML). For a given forwarding class, you can include either the multilink-class or no-fragmentation statement; they are mutually exclusive. For more information about MCML, see Configuring Multiclass MLPPP.
To associate a fragmentation map with a multilink PPP interface or MLFR FRF.16 DLCI, include the fragmentation-map statement at the [edit class-of-service interfaces interface-name unit logical-unit-number] hierarchy level:
- [edit class-of-service interfaces]
- lsq-fpc/pic/port {
- unit logical-unit-number { # Multilink
PPP
-
fragmentation-map map-name;
- }
- lsq-fpc/pic/port:channel { # MLFR FRF.16
- unit logical-unit-number {
-
fragmentation-map map-name;
- }
For configuration examples, see Common Uses for the Link Services IQ Interface.
For Link Services PIC link services interfaces (ls), fragmentation maps are not supported. Instead, you can enable LFI by including the interleave-fragments statement at the [edit interfaces interface-name unit logical-unit-number] hierarchy level. For more information, see Configuring Link Services Delay-Sensitive Packet Interleaving.