Specifications

Setting Up Secure Survivable Remote Site Telephony
Restrictions for Setting Up Secure SRST
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Cisco Unified Survivable Remote Site Telephony Version 4.0 System Administrator Guide
• Gateway routers that run secure SRST must support voice- and security-enabled Cisco IOS images
(a “k9” cryptographic software image). The following two images are supported:
– Advanced IP Services. This image includes a number of advanced security features.
– Advanced Enterprise Services. This image includes full Cisco IOS software.
Public Key Infrastructure
• Set the clock, either manually or by using Network Time Protocol (NTP). Setting the clock ensures
synchronicity with Cisco Unified CallManager.
• Enable the IP HTTP server (Cisco IOS processor) with the ip http server command, if not already
enabled. For more information on public key infrastructure (PKI) deployment, see the Cisco IOS
Certificate Server feature.
• If the certificate server is part of your startup configuration, you may see the following messages
during the boot procedure:
% Failed to find Certificate Server's trustpoint at startup
% Failed to find Certificate Server's cert.
These messages are informational messages and indicate a temporary inability to configure the
certificate server, because the startup configuration has not been fully parsed yet. The messages are
useful for debugging, in case the startup configuration has been corrupted.
You can verify the status of the certificate server after the boot procedure using the show crypto pki
server command.
SRST
• Secure SRST services cannot be enrolled while SRST is active. Therefore disable SRST with the no
call-manager-fallback command.
Supported Cisco Unified IP Phones, Platforms, and Memory Requirements
• For a list of supported Cisco IP phones, routers, network modules, and codecs for secure SRST, see
the Media and Signaling Authentication and Encryption Feature for Cisco IOS MGCP Gateways
feature.
• For the most up-to-date information about the maximum number of Cisco Unified IP Phones, the
maximum number of directory numbers (DNs) or virtual voice ports, and the memory requirements
for Cisco Unified SRST 4.0 Supported Firmware, Platforms, Memory, and Voice Products at
http://www.cisco.com/en/US/customer/products/sw/voicesw/ps2169/prod_installation_guide09186
a00805f6f1b.html..
Restrictions for Setting Up Secure SRST
General
• Cryptographic software features (“k9”) are under export controls. This product contains
cryptographic features and is subject to United States and local country laws governing import,
export, transfer, and use. Delivery of Cisco cryptographic products does not imply third-party
authority to import, export, distribute or use encryption. Importers, exporters, distributors and, users
are responsible for compliance with U.S. and local country laws. By using this product you agree to
comply with applicable laws and regulations. If you are unable to comply with U.S. and local laws,
return this product immediately.
A summary of U.S. laws governing Cisco cryptographic products may be found at: