Polycom 1725-11530-200 Rev A1 manual Ethernet Switch, Application Network Setup

Administrator’s Guide - SoundPoint® IP / SoundStation® IP Optimization

4 Optimization

4.1 Ethernet Switch

The SoundPoint® IP phones contain two Ethernet ports, labeled LAN and PC, and an embedded Ethernet switch that runs at full line-rate. The Ethernet switch allows a per- sonal computer and other Ethernet devices to connect to the office LAN by daisy chaining through the phone, eliminating the need for a stand-alone hub. The SoundPoint® IP switch gives higher transmit priority to packets originating in the phone. SoundPoint® IP can be powered through a local AC power adapter or can be line-powered (power supplied through the signaling or idle pairs of the LAN Ethernet cable). Line powering typically requires that the phone plugs directly into a dedicated LAN jack. Devices that do not require LAN power can then plug into the SoundPoint® IP PC Ethernet port.

SoundPoint® IP Switch - Port Priorities

To help ensure good voice quality, the Ethernet switch embedded in the

SoundPoint® IP phones should be configured to give voice traffic emanating from the phone higher transmit priority than those from a device connected to the PC port. If not using a VLAN (VLAN blank in the setup menu), this will automatically be the case. If using a VLAN, ensure that the 802.1p priorities for both default and real-time transport protocol (RTP) packet types are set to 2 or greater. Otherwise, these packets will compete equally with those from the PC port. For more information, refer to

4.6.1.9Quality of Service <QOS/> on page 118.

4.2Application Network Setup

4.2.1 Real-Time Transport Protocol Ports

The phone is compatible with RFC 1889 - RTP: A Transport Protocol for Real-Time Applications - and the updated RFCs 3550 and 3551. Consistent with RFC 1889, the phone treats all RTP streams as bi-directional from a control perspective and expects that both RTP end points will negotiate the respective destination IP addresses and ports. This allows real-time transport control protocol (RTCP) to operate correctly even with RTP media flowing in only a single direction, or not at all. It also allows greater security: packets from unauthorized sources can be rejected.

Copyright © 2006 Polycom, Inc. 77