[Asterisk-Users] Cisco IP Phones - FYI

[Rich Adamson]

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