Cisco IOS Software Releases 12.1 Special and Early Deployments

Cisco IOS Software Release 12.1(1)XC

Document ID: 20309

Early Deployment (ED) Release Summary

[an error occurred while processing this directive] [an error occurred while processing this directive] [an error occurred while processing this directive] [an error occurred while processing this directive]


Cisco IOS® Software Release 12.1(1)XC is a short-lived release based on 12.1(1)T (XED). It has been optimized to provide support for the hardware encryption card of the Cisco 1720 and 1750 access voice-enabled routers.

To increase security, the integrated Cisco IOS software and the encryption card protects internal LANs from attacks with dynamic access control, while IPSec tunneling with DES (data encryption standard) and Triple DES encryption provide standards-based data privacy, integrity and authenticity as data travels through a public network. Layer 2 Forwarding (L2F) and Layer 2 Tunneling Protocol (L2TP) combine with IPSec encryption to provide a secure multiprotocol solution(such as IP, IPX, AppleTalk, and more) for remote access VPN. Mobile users dial in to a service provider's local points of presence (POPs) and data is "tunneled" (for example, encapsulated inside a second protocol such as L2TP) back to the Cisco 1720 router in order to securely access the corporate network via the Internet. With Cisco IOS Software Release 12.1(1)XC, part of the encryption is now performed in the hardware encryption card.

The following links provide further details:

Product Support

Major New Features


Memory Requirements
Flash Mem / Dram Mem

  • Hardware encryption card.
  • Voice features
  • DNS,DHCP, NAT, PAP, L2F, L2TP features

Cisco 1750 & 1720






8MB     32MB

8MB     32MB

8MB     32MB

8MB     32MB

Based On (root)

Ported Into

Maintenance Release Synchronization Points

Cisco IOS Software Release 12.1(1)T

Cisco IOS Software Release 12.1(3)T

Maintenance Release

Cisco IOS Software Release 12.1(1)XC is a one-time release or XED

Target Market

Cisco IOS Software Release 12.1E is for general purpose use by Enterprise and Network Service Providers, ISP, SOHO, SMB.

Interim Builds

Weekly Builds. IOS XED do not provide interim, they may provide rebuilds to address catastrophic defects.

Customers are advised to upgrade to next fully tested maintenance revision.

Recommended Customer Migration Path

Customer Upgrade From

Customer Upgrade to

Cisco IOS 12.0(5)XQ

12.1(1)XC, 12.1.3aT7 for 1720 or 12.1.5T10 for both 1720 & 1750

The recommended migration path is the logical superseding release, which brings additional features and hardware support to the network without loss of previously configured functionality.

Life Cycle


Y2K Compliance


Other Dates

CCO FCS: 3/20/00







MFG FCS: 3/27/00

Support Pages:

Updated: Feb 18, 2003 Document ID: 20309