Programming instructions

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CXi/MXe Requirements for IP Networking
LAN Requirements
• A subnet with IP addresses reserved for the following:
- the CXi/MXe system
- the internal Layer 2 switch
- the system gateway (router on the LAN or the CXi/MXe itself)
- static IP addresses or DHCP-assigned addresses for IP phones
(DHCP-assigned addressing is recommended).
• A Dynamic Host Configuration Protocol (DHCP) server within the
Broadcast Domain. The CXi and MXe include a DHCP server.
• Optional:
- a router or firewall on the same subnet as the CXi/MXe. (Note that
firewall (including NAT) is on by default for incoming connectivity
from the Internet via the WAN port.)
- external Layer 2 switches (unmanaged for a voice only; managed
and VLAN-capable for a voice and data implementation). The CXi
supports as many switches as required but you cannot exceed the
maximum 64 IP users.
- SMTP server address to support e-mail forwarding
- DNS server address; external DHCP server information;
- one PC per IP phone (phones must be dual-port models); PCs
must have 10/100BaseTx Ethernet cards.
Tip: Refer to the Engineering Guidelines, Network Configuration for CXi- and
MXe-specific guidelines and, configuration and programming requirements.
Tip: IP phones/IP devices should only be served by one DHCP server.
Tip: Layer 2 switches should only be connected to Port 17 on the CXi and
the left Gigabit port on the MXe. This rule lessens the chance of spanning
tree issues (loops in the network).
Tip: IP trunks cannot work through the WAN port.