Meridian Nortel 1 Option 11C Technical Reference Manual page 185

Figure 16
Example of third-party media device used with 100BaseT hardware
IP Security
Cabinet distribution over a data network
Media conversion devices
Third-party media conversion devices can be used to extend the range of the
100BaseT and 100BaseF IP solutions. One such device, the IMC Networks
Ethernet Compatible Media Converter with a McLIM Tx/Fx-SM/Plus
module, provides acceptable transmission between cabinets located up to 40
km apart. This solution is illustrated in Figure 16. However caution must be
used when extending the length of cable used in the point-to-point
configuration. The round trip delay parameters specified in Table 57 must not
be exceeded.
IP security in IP Expansion configuration is addressed in two ways:
• Filtering to protect CPU integrity and call processing stability.
— ARP Filtering - ARPs are filtered when the IP link between Main
cabinet and IP Expansion cabinet is up.
— IP Filtering - Only packets from/to M1 nodes (cabinets) IP addresses
are processed when the IP link between the Main cabinet and IP
Expansion cabinet is up.
Note: IP Expansion cabinets, during IP link up mode, cannot be
"pinged" from other data network nodes. However the Main cabinet can
ping IP Expansion cabinets and vice-versa.
• Voice Channels Security (Privacy)
— Multiplexed Voice Channels Packets - PCM samples from all active
channels are packetized every 125usec. There is no single voice
packet associated with the call as with standard VoIP protocols.
Option 11C and 11C Mini
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Technical Reference Guide