lxt9785 Intel Corporation, lxt9785 Datasheet - Page 150

• Manufacturer Part Number: lxt9785
• Description: Advanced 8-port 10/100 Mbps Phy Transceivers
• Manufacturer: Intel Corporation

LXT9785 and LXT9785E Advanced 8-Port 10/100 Mbps PHY Transceivers
4.11
4.11.1
152
Figure 29. Typical IP Telephone System Connection
DTE Discovery Process
The DTE discovery process is port dependent and must be enabled through software. The process
is implemented as a next page option to the auto-negotiation flow. When the process is enabled,
manual control of auto-negotiation next pages is not allowed. This feature applies to the
LXT9785E transceiver only.
The process depends upon an IP phone, or any other DTE capable of being powered remotely,
having a specific filter that passes NLPs and FLPs. This filter should be non-polarized to insure
that the latest status of Auto-MDIX operation does not effect operation. This filter attenuates
100 Mbps MLT3 signals and 10 Mbps Manchester-encoded signals, and must be bypassed when
power is applied to the IP phone.
Definitions
The following terms are used throughout the DTE discovery sections:
Negotiation Process:
System:
Link Partner:
DTE:
Standard Link Partner:
Remote-Power DTE:
Discovery:
Power
Outlet
Power cable
Generator
UPS/
This includes auto-negotiation and parallel detection processes
The switch system using the LXT9785E for DTE Discovery
A device connected to the LXT9785E through twisted pair cables
Data Terminal Equipment; any end-of-link partner
A link partner that is not requiring power over a Category 5 cable;
typically a PC
Data Terminal Equipment requiring power over a Category 5 cable;
typically an IP telephone
The process of identifying the type of link partner present
Figure 29
Power
Fault
Pr oCurve Switch 2424M
HP J4122B
Console
Module Status
Self Test
VoIP-Enabled Switch
Reset
1 2 3
7 8 9 10 11 12
Clear
4 5
6
13 14 1 5 16 17 18
19
Mode Select
20
Act
2 1
Fdx
22 23 24
100
Link
Mode
Link
Mode
IP Telephone
1X
7X
shows a typical IP telephone system connection.
2X
8X
3X
9X
10X
4X
5X
11X
6X
12X
1 2 3
4 5 6
7 8 9
*
8 #
10/100Base -T Ports
13X
19X
14X
20X
15X
21X
16X
22X
17X
23X
18X
24X
SD
Power and data over
Category 5 cable
Data only over
Category 5 cable
Computer
Revision Date: August 28, 2003
Document Number: 249241
Power cable
Revision Number: 007
Power
Outlet
Datasheet