# Supported MLFR Features

E Series routers support the following MLFR features on the cOCx/STMx and CT3 line modules:

- Logical aggregation of up to eight T1 or E1 links in a bundle
- Monotonically increasing sequence numbers for each circuit

  All packets distributed across the member links have monotonically increasing sequence numbers for each circuit. This feature enables the remote router on the customer premises to perform resequencing (if it is configured to do so).

- Static configuration of the links participating in a multilink bundle
- Round-robin packet distribution
  - On CT3 line modules, packet distribution across the member links in a bundle is handled only in a round-robin fashion. The round-robin approach is used even when the member links have different line rates.
  - On cOCx/STMx and COCX-F3 line modules, the router keeps track of the link with the least traffic. If this link cannot forward a packet, the router attempts to forward the traffic on a different link. If this attempt also fails, the router uses a round-robin approach.

You can configure bundles as follows:

- On a cOCx/STMx line module and its corresponding I/O modules, you can configure:
  - Member links from different OC3/STM1 ports in the same bundle
  - The 336 available T1 channels combined in any manner that does not exceed 8 links per bundle (for example, 336 single-link T1 bundles, 42 eight-link bundles, or 41 eight-link bundles and 8 single-link bundles)
  - The 252 available E1 channels combined in any manner that does not exceed 8 links per bundle (for example, 252 single-link E1 bundles, 34 eight-link bundles, or 33 eight-link bundles and 8 single-link bundles)
- On a COCX-F3 line module and its corresponding I/O modules, you can configure:
  - Up to 8 member links from different ports in the same bundle
  - Up to 12 bundles
- On a CT3 or CT3/T3-F0 line module and its corresponding I/O module, you can configure:
  - Only member links from the same T3 interfaces into the same bundle. You cannot configure member links from different T3 ports in the same bundle.
  - The 28 available T1 channels on each port combined in any manner that does not exceed 8 links per bundle (for example, 28 single-link T1 bundles or 3 eight-link bundles and 4 single-link bundles per port)
- You can configure IPv6 addresses on Frame Relay subinterfaces in an MLFR bundle that contains serial interfaces as member links. MLFR bundles with IPv6 addresses enable effective usage of bandwidth and reduced administrative costs.