Feature History For Single-Vc Mlp Over Atm-Based Lfi; Fragment Size Calculation For Mlp Over Atm-Based Lfi - Cisco 10000 Series Configuration Manual

Chapter 16 Fragmenting and Interleaving Real-Time and Nonreal-Time Packets
The following describes how MLP implements fragmentation and interleaving:
•
•
When configuring single-VC MLP over ATM-based LFI, you must configure a virtual template interface
for the MLP bundle. However, the virtual template does not need to be unique for each bundle—multiple
MLP bundles can share the same virtual template.
For more information about MLP, see the
section on page 16-11
MPLS Configuration

Feature History for Single-VC MLP Over ATM-Based LFI

Cisco IOS Release
Release 12.2(27)SBB The single-VC MLP over ATM-based LFI feature was
Release 12.2(31)SB2

Fragment Size Calculation for MLP Over ATM-Based LFI

For MLP over ATM-based LFI, the ideal fragment size should allow the fragments to fit into an exact
multiple of ATM cells.
over ATM-based LFI. As shown in the table, the minimum fragment size depends on the AAL5
encapsulation type used and whether or not protocol compression is enabled.
Table 16-2
AAL5 Encapsulation Type
AAL5 MUX
AAL5 SNAP
AAL5 Cisco
AAL5 MUX
AAL5 SNAP
AAL5 Cisco
OL-7433-09
Delay-Sensitive, Real-Time Packets—On transmit, MLP encapsulates the packets as PPP over ATM
(PPPoA) and sends the packets to a special transmit queue to enable the router to transmit the
real-time packets earlier than other packet flows. The router interleaves the real-time packets
between the fragments of the larger, nonreal-time packet over a single point-to-point link to the
remote address. Upon receipt, the receiving fragmentation peer processes the real-time packets as
PPPoA packets.
Delay-Insensitive, Nonreal-Time Packets—On transmit, MLP fragments the large data packets to a
size small enough to satisfy the delay requirements of real-time traffic. MLP encapsulates the
packets as MLP packets and sends the packets to a transmit queue to enable the router to transmit
the fragments at the same time over multiple point-to-point links to the same remote address. The
receiving fragmentation peer reassembles the fragments to the original packet and then processes it
as Point-to-Point Protocol over ATM (PPPoA). The underlying PPP encapsulation conforms to
RFC 1661. All outbound MLP packets with a payload larger than the specified fragment size are
fragmented. The minimum fragment size depends on the AAL5 encapsulation type and whether or
not protocol compression is enabled (see
and the
Guide.
Description
introduced on the router for the PRE2.
This feature was introduced on the PRE3.
Table 16-2
ATM Minimum Fragment Size
Protocol Compression
OFF
OFF
OFF
ON
ON
ON
Multilink PPP-Based Link Fragmentation and Interleaving
Table 16-2 on page
"Multilink PPP-Based Link Fragmentation and Interleaving"
Cisco 10000 Series Router Broadband Aggregation, Leased-Line, and
lists the minimum fragment sizes for Single-VC and Multi-VC MLP
Minimum Fragment Size
82 Bytes
78 Bytes
80 Bytes
83 Bytes
79 Bytes
81 Bytes
Cisco 10000 Series Router Quality of Service Configuration Guide
16-15).
Required PRE
PRE2
PRE3
16-15