Cisco ASR 903 Release Notes

CHAPTER
1
Cisco IOS XE 3S Release Notes for the Cisco ASR 903 Router
OL-26630-08
5
Restrictions and Caveats in Cisco IOS XE 3.9
Releases
This chapter provides information about restrictions and caveats in Cisco IOS XE 3.9 releases.
Note We recommend that you view the field notices for the current release to determine whether your software
or hardware platforms are affected. You can access field notices at
http://www.cisco.com/en/US/support/tsd_products_field_notice_summary.html.
This chapter contains the following sections:
• Limitations and Restrictions, page 1
• Caveats in Cisco IOS XE 3.9S Releases, page 5
Limitations and Restrictions
The following limitations apply to the Cisco ASR 903 Router in IOS XE Release 3.9(0)S and later:
ATM IMA Limitation
• You can create a maximum of 16 IMA groups on each T1/E1 interface module.
Bidirectional Forwarding Detection Limitations
• The minimum supported timer value for software-based BFD sessions is 200 ms x 3 (using a
multiplier of 3). The router supports up to 64 offloaded BFD sessions using a 200 ms x 3 timer.
• The Cisco ASR 903 Router supports hardware offloading of BFD echo mode packets for up to 255
sessions. The router handles additional BFD echo mode sessions in software.
Note You cannot convert more than 255 normal BFD sessions to echo mode BFD sessions; the router
reaches the offload limit and you must remove and reconfigure the remaining sessions.
• The minimum supported timer value for offloaded BFD echo mode sessions is 3.3 ms.
• In Release 3.9, the router keeps hardware and software-handled BFD echo mode sessions active
during ISSU. Releases prior to 3.9 do not maintain hardware-offloaded BFD echo mode sessions
during ISSU.

Cisco ASR 903 Specifications

General

Brand	Cisco
Model	ASR 903
Category	Network Router
Language	English