Cisco Ip Phone 8800 Series Administration Guide For Cisco Unified Communications Manager - Cisco 8800 Series Administration Manual

Supported Security Features
• Cisco Centralized Key Management (CCKM): Uses RADIUS server and a wireless domain server
(WDS) information to manage and authenticate keys. The WDS creates a cache of security credentials
for CCKM-enabled client devices for fast and secure reauthentication. The Cisco IP Phone 8800 Series
supports 802.11r (FT).
With WPA/WPA2 and CCKM, encryption keys are not entered on the phone, but are automatically derived
between the AP and phone. But the EAP username and password that are used for authentication must be
entered on each phone.
To ensure that voice traffic is secure, the Cisco IP Phone supports WEP, TKIP, and Advanced Encryption
Standards (AES) for encryption. When these mechanisms are used for encryption, both the signalling SIP
packets and voice Real-Time Transport Protocol (RTP) packets are encrypted between the AP and the Cisco
IP Phone.
WEP
With WEP use in the wireless network, authentication happens at the AP by using open or shared-key
authentication. The WEP key that is setup on the phone must match the WEP key that is configured at
the AP for successful connections. The Cisco IP Phone supports WEP keys that use 40-bit encryption
or a 128-bit encryption and remain static on the phone and AP.
EAP and CCKM authentication can use WEP keys for encryption. The RADIUS server manages the
WEP key and passes a unique key to the AP after authentication for encrypting all voice packets;
consequently, these WEP keys can change with each authentication.
TKIP
WPA and CCKM use TKIP encryption that has several improvements over WEP. TKIP provides
per-packet key ciphering and longer initialization vectors (IVs) that strengthen encryption. In addition,
a message integrity check (MIC) ensures that encrypted packets are not being altered. TKIP removes
the predictability of WEP that helps intruders decipher the WEP key.
AES
An encryption method used for WPA2 authentication. This national standard for encryption uses a
symmetrical algorithm that has the same key for encryption and decryption. AES uses Cipher Blocking
Chain (CBC) encryption of 128 bits in size, which supports key sizes of 128, 192 and 256 bits, as a
minimum. The Cisco IP Phone supports a key size of 256 bits.
The Cisco IP Phone does not support Cisco Key Integrity Protocol (CKIP) with CMIC.
Note
Authentication and encryption schemes are set up within the wireless LAN. VLANs are configured in the
network and on the APs and specify different combinations of authentication and encryption. An SSID
associates with a VLAN and the particular authentication and encryption scheme. In order for wireless client
devices to authenticate successfully, you must configure the same SSIDs with their authentication and encryption
schemes on the APs and on the Cisco IP Phone.
Some authentication schemes require specific types of encryption. With Open authentication, you can use
static WEP for encryption for added security. But if you are using Shared Key authentication, you must set
static WEP for encryption, and you must configure a WEP key on the phone.

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