Secure Call Implementation; Enabling Secure Calls - Cisco WRP400-G1 - Wireless Router Administration Manual

Secure Call Implementation

Secure Call Implementation
NOTE
Cisco Small Business WRP400 Administration Guide
This section describes secure call implementation with the WRP400 . It includes
the following topics:
• "Enabling Secure Calls" section on page 52
• "Secure Call Details" section on page 53
• "Using a Mini-Certificate" section on page 54
• "Generating a Mini Certificate" section on page 55
This is an advanced topic meant for experience installers. Also see the
Guide at the following URL:
www.cisco.com/en/US/docs/voice_ip_comm/csbpvga/ata/provisioning/guide/
Cisco_Small_Business_IP_Telephony_Provisioning_Guide.pdf

Enabling Secure Calls

A secure call is established in two stages. The first stage is no different from
normal call setup. The second stage starts after the call is established in the
normal way with both sides ready to stream RTP packets.
In the second stage, the two parties exchange information to determine if the
current call can switch over to the secure mode. The information is transported by
base64 encoding embedded in the message body of SIP INFO requests, and
responses using a proprietary format. If the second stage is successful, the
WRP400 plays a special Secure Call Indication Tone for a short time to indicate to
both parties that the call is secured and that RTP traffic in both directions is being
encrypted.
If the user has a phone that supports call waiting caller ID (CIDCW) and that
service is enabled, the CID will be updated with the information extracted from the
Mini-Certificate received from the remote party. The Name field of the CID will be
prepended with a '$' symbol. Both parties can verify the name and number to
ensure the identity of the remote party.
3
Provisioning
52