Limitations And Restrictions With Pots Splitters - Cisco Catalyst 2950 Hardware Installation Manual

Chapter 3 Installation

Limitations and Restrictions with POTS Splitters

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If the installation does not have a PBX, you need to use a homologated POTS
splitter to connect to the PSTN. For more information about homologated POTS
splitters, contact your Cisco sales representative.
If a connection to a telephone network is not required, you do not need a splitter,
and you can connect the switch to the patch panel.
These limitations and restrictions apply when you use a POTS splitter with
Catalyst 2950 LRE switches and Cisco LRE CPE devices:
The Catalyst 2950ST-8 LRE switch, Catalyst 2950ST-24 LRE switch,
•
Cisco 575 LRE CPE, and Cisco 585 LRE CPE are designed to share lines
with analog, ISDN, and digital PBX switch telephones that use the 0
to 700 kHz frequency range.
Digital telephones connected to digital PBX switches that use frequencies
above 700 kHz do not work when sharing a line with LRE signals. Due to the
proprietary nature of digital PBX switches, some digital PBX switch services
use frequencies above 700 kHz.
You can use a Cisco LRE 48 POTS Splitter with a Catalyst 2950ST-8 LRE
•
switch, Catalyst 2950ST-24 LRE switch, Cisco 575 LRE CPE, and Cisco 585
LRE CPE. For installation instructions, refer to the Installation and Warranty
Notes for the Cisco LRE 48 POTS Splitter.
• The Catalyst 2950ST-24 LRE 997 switch and Cisco 576 LRE 997 CPE are
designed to share lines with analog and ISDN telephones that use the 0
to 120 kHz frequency range.
We recommend that you do not use a Cisco LRE 48 POTS Splitter with a
•
Catalyst 2950ST-24 LRE 997 switch and a Cisco 576 LRE 997 CPE as shown
in Figure 3-35. Only traffic in a specific frequency range can be sent to and
from the devices attached to the CPE.
In Figure 3-35, only traffic from 0 to 120 kHz can pass from a device attached
to the CPE, such as a computer or telephone, to the CPE, a splitter, and a
switch. In the reverse direction, traffic from 0 to 700 kHz can pass through
the switch and splitter to the CPE, but only traffic from 0 to 120 kHz can pass
through the CPE to a computer or a telephone.
For more information, refer to the Installation and Warranty Notes for the
Cisco LRE 48 POTS Splitter.
Catalyst 2950 Desktop Switch Hardware Installation Guide
Connecting to an LRE Port
3-39