MX2800 STS-1 User Manual Configuration, Section 3Network Interface61204659L1-1A 3-7VT ModeThe seven VT groups may be configured to carry either VT1.5 or VT2 tributaries.• When set for VT1.5 (T1), all VT groups are set for VT1.5[TU=11] at 1.728 Mbps and the ports are setfor T1 at 1.544 Mbps.• When set for VT2 (E1), all the VT groups are set for VT2[TU=12] at 2.304 Mbps and the ports are setfor E1 at 2.048 Mbps. When set for VT2, the last 7 VTs (VT 22-28), and the last 7 ports (ports 22-28)become unavailable.Protection ConfigurationThe MX2800 STS-1 houses two controller cards for 1:1 protection against hardware failure. The two cardscan also provide network protection, supporting two STS-1 circuits simultaneously. The menu selectionsallow customization of setup parameters.Active ControllerThis field displays A or B, indicating the active controller card. This setting can be used to force thecontroller cards to switch. For example, if controller card A is active and B is selected, a switch-overoccurs immediately.Network ProtectionThis option allows enabling or disabling of the ability to automatically route the STS-1 to the backup facil-ity in the event of a facility failure.• Network Protection = Enabled: All information is automatically routed to the backup facility in theevent of a primary facility failure.• Network Protection = Disabled: The primary STS-1 facility (A) is utilized at all times.NOTEWhen choosing a setting for Network Protection, cabling and networkprovisioning issues must be considered. For configuration examples ofthe different modes of protection, refer to Section 7, Circuit Redundancy.Max. (Maximum) Switch ThresholdThe value entered in this field determines the number of times per hour the unit is allowed to switchbetween controller cards. If protection switching occurs more than the Max. Switch Threshold within onehour, the unit issues a trap and inhibits automatic protection switching for the next 24 hours. The defaultsetting is 3 times an hour. This count may be cleared by clearing protection switch alarm counts (refer toProtection Switch Statistics on page 5-13).
