distributed Link Fragmentation and Interleaving (dLFI) over:
•Frame Relay (dLFIoFR)
•Leased lines (dLFIoLL)
Supported only on multilink interface with a single member link. 3
MPLS is not supported with dLFI.
MPLS-VPN is supported between the CE and PE. VRF is also supported between CE and PE.
PPPoMPLS is not supported with dLFI. 2
Supported on dLFIoLL.
Not supported on dLFIoFR or dLFIoATM.
Link fragmentation and interleaving (LFI) is always done in the software. 4
In addition, the following guidelines apply to fragmentation:
•For software-based dMLP (which is performed at the line card), the ppp multilink interleave command is required to enable fragmentation. For hardware-based MLP (on the SPA), fragmentation can be enabled through the ppp multilink fragmentation command.
•For dMLFR, fragmentation on the TX side is not supported.
2PPPoMPLS is not supported with dMLP and dLFI. This is because PPPoMPLS must be configured end-to-end, while dMLP and dLFI are terminated (since they use point-to-point protocol).
3cRTP and dLFI can be used together only if the multilink interface has a single link. On an interface with multiple links, dLFI distributes priority packets (such as VoIP) across all of the links. Since priority packets do not contain the MLP header and sequence number, the packets could arrive out of sequence. cRTP does not support out-of-sequence packets; therefore, cRTP and dLFI cannot be used on a multilink interface with multiple links.
4LFI is always done in the software with the exception of dLFIoATM on a SIP-100/ATM-SPA, in which case LFI is done in the SPA. In addition, when running dLFIoLL with a single member link in the bundle on a SIP-200 SPA, LFI is done at the hardware level.