4
Cisco IOS XE 3S Release Notes for the Cisco ASR 903 Router
OL-26630-12
Chapter
Limitations and Restrictions
MLPPP Limitations
The following limitations apply when using MLPPP on the Cisco ASR 903 Router:
•
All links in an MLPPP bundle must be on the same interface module.
•
All links in an MLPPP bundle must be of the same bandwidth.
•
The Cisco ASR 903 Router supports a maximum of 8 links per bundle
•
To change the MLPPP bundle fragmentation mode between enabled and disabled, perform a
shutdown
/
no shutdown
on the bundle.
•
LFI is not supported
•
Multiclass MLP is not supported
•
The Cisco ASR 903 Router supports MLPPP statistics with the following limitations:
–
Packet counters on the bundle display the number of fragments rather than packets.
–
Control packets are accounted on the bundle.
•
If you increase the maximum transmission unit (MTU) size on an MLPPP interface to a value higher
than the maximum received reconstructed unit (MRRU) value on the peer interface, this can bring
the MLPPP tunnel down. To restore the tunnel, perform a shutdown/no shutdown on the interface.
MPLS VPN Limitation
•
MPLS VPN (L3VPN) Fragmentation does not function properly if an access interface has a higher
MTU value than a core interface. To ensure that fragmentation functions correctly, configure the
core interface MTU with a value that exceeds the access interface MTU and relevant headers.
OC-3 IM Limitations
•
The
configure replace
command is not supported on the OC-3 IMs.
•
SDH framing mode is supported; SONET is not supported.
•
The optical interface module is designed for OC-3 and OC-12 traffic, but OC-12 functionality is not
currently supported.
•
If you issue the
no card type
command on the controller, you must reload the router in order to
configure a new
card type
value.
•
We recommend that you use Release 3.7.2 or later when using the OC-3 IM with high availability
(HA) features such as stateful switchover (SSO).
Pseudowire/AToM Limitation
•
The Cisco ASR 903 Router supports ATM over MPLS N-to-one cell mode for a single ATM Virtual
Channel Connections (VCCs) or Permanent Virtual Circuits (PVCs) to a pseudowire, but does not
support mapping to multiple VCCs or PVCs.
•
The Cisco ASR 903 Router does not support ATM over MPLS one-to-one cell mode.
•
The Cisco ASR 903 Router supports pseudowire ping using the CW method; pseudowire ping using
the TTL method is not supported.
•
The Cisco ASR 903 Router supports a maximum of 2000 pseudowires in any combination.
QoS Limitations
•
For a description of QoS features and limitations on the Cisco ASR 903 Router in release 3.7S, see
http://www.cisco.com/en/US/docs/routers/asr903/software/guide/chassis/Release3.7.0S/ASR903-
Chassis-SW-37.html
.