I’ve reverse engineered the encoding used in the Microsoft NSC format and written a decoder. Here’s how Cisco describes NSC:

A multicast description file is required at the Cisco content engine’s Windows Media Technology Server. This description file, in the form of an .nsc file, is received from a known URL, mount point, or even via email. This file is also referred to as an “announcement.” The source path follows the standards based URL format: http://www.cisco.com/path/filename.nsc. … the structure of the .nsc file is protected with the use of encryption. This is used to protect the media from network sniffing of the media source’s IP address, port, and stream format.

That it’s encryption is a faulty assumption (or bullshit marketing) on Cisco’s part. The algorithm doesn’t take a key.

Download: nscdec.c (MD5: 7c81ca49bc68c2b8671d00f0cdf960e3)

Example usage: $ nscdec 02AW000000000SLm1D0580HG1C0440MG0m0380800i0200GG0000 Encoding type: 2 Decoded string: [WMRELAY02 , A]

Update: VLC should have NSC support in the near future.