Just attended the Cisco Networkers conference and sat through a presentation addressing in part the Cisco IP phones. All was presented openly without the need for disclosures, etc.

The following is simply an FYI from the presentation, FWIW.

Existing IP Phones (7905/7912/7940/7960):
 Transport: UDP
 Call Signalling: rfc2833
 Security: Digest Auth
 Feature parity to SCCP: None

Sip Enhanced Phones (7911/7941/7961/7971/7970):
 Transport: UDP/TCP/TLS
 Call Setup: KPML and Dial Rules (KPML sends each dialed digit in a
   packet)
 Call Signaling: KPML, rfc2833
 Security: CAPF/CTL/TLS
 Feature parity to SCCP: Almost the same (will be later)

Notes:
1. All cisco phones with dual rj45's pass BPU packets (spanning tree) through internal switch ports. The switch is a non-mac-address-learning switch. 2. Cisco Discovery Protocol (CDP) is implemented in the phones and is used to discover the VLAN number (for rtp traffic), and to pass PoE power requirements to the closet switch. Per 802.3af, 3 power levels are possible. The 7960 requires 6.3 watts. If the switch doesn't support CDP, the switch will have to assume the highest power consumption. 3. Future releases of cisco's enhanced sip will provide the same features as the SCCP (skinny) phone images. 4. Early models of the 7912 phone had a hardware problem with QoS that can't be fixed. Later 7912's the problem was fixed.

Rich


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