Cisco Multiservice Switching Networks

MGX-8850 and MGX-8950-based PNNI nodes as well as Cisco IOS Software-based PNNI platforms support NCDP as a network application for clock distribution.

In MGX-8850 and MGX-8950 PNNI switches, physical links are enabled as NCDP ports, and virtual links are disabled by default. See Example 10-34.

NOTE

You may need to enable NCDP using the command cnfncdp -distributionMode 1.

Example 10-34. Displaying NCDP Ports

m8950-7b.7.PXM.a > dspncdpports PortId Clock mode Clock Vpi Clock Vci Admin Cost Ncdp Vc 1:1.1:1 enable 0 34 10 up 5:1.1:1 disable 10 34 10 down m8950-7b.7.PXM.a >

In your network scenario, you can enable NCDP on port 5:1.1:1 in the MGX-8950 and corresponding port 12:1.1:1 in the MGX-8850 (see Example 10-35) because they are directly connected. You need to understand that pnport 5:1.1:1 is a logical port using a range of VPIs only.

Example 10-35. Enabling NCDP on Two Ports

m8950-7b.7.PXM.a > cnfncdpport 5:1.1:1 -ncdp enable m8950-7b.7.PXM.a > dspncdpports PortId Clock mode Clock Vpi Clock Vci Admin Cost Ncdp Vc 1:1.1:1 enable 0 34 10 up 5:1.1:1 enable 10 34 10 up m8850-7a.7.PXM.a > cnfncdpport 12:1.1:1 -ncdp enable

Next you configure the external clock input number 1 in the MGX-8850 as an NCDP clock source with priority 10 (the default priority is 128). See Example 10-36.

Example 10-36. Creating NCDP Clock Sources

m8850-7a.7.PXM.a > cnfncdpclksrc 7.35 0 t1 -priority 10 -stratumLevel 2 m8850-7a.7.PXM.a > dspncdpclksrcs PortId Best clk src Priority Stratum level Prs id Health 7.35 (t1) Yes 10 2 0(external) Good 255.255 No 128 3 255(internal) unknown m8850-7a.7.PXM.a >

The NCDP clock source 255.255 refers to the node's internal oscillator.

You also configure the MGX-8950 internal oscillator as a second NCDP clock source with a lowest priority (highest priority number). Refer to Example 10-37.

Example 10-37. Configuring a Secondary NCDP Clock Source

m8950-7b.7.PXM.a > cnfncdpclksrc 255.255 255 -priority 100

The MGX-8950 gets clock from interface 5:1.1:1 facing the MGX-8850. You can see this using the command dspncdp, as shown in Example 10-38.

Example 10-38. Displaying NCDP Status

m8950-7b.7.PXM.a > dspncdp Distribution Mode : ncdp Node stratum level : 3 Max network diameter : 20 Hello time interval : 500 Holddown time interval : 500 Topology change time interval : 500 Root Clock Source : 5:1.1:1 Root Stratum Level : 2 Root Priority : 10 Last clk src change time : Feb 20 2002 14:36:31 Last clk src change reason : Topology Changed m8950-7b.7.PXM.a >

You can enable NCDP in the Cisco IOS Software-based platform using the global configuration command ncdp, as shown in Example 10-39.

Example 10-39. Enabling NCDP in Cisco IOS

LS-1010#conf t Enter configuration commands, one per line. End with CNTL/Z. LS-1010(config)#ncdp LS-1010(config)#^Z LS-1010# 2d11h: %CLOCKSW: Switching from System to ATM0/1/0

You can see the LS1010 clock status using the command show ncdp status (see Example 10-40). Note that the clocking root AESA corresponds to the MGX-8850 node.

Example 10-40. Showing NCDP Status in Cisco IOS

LS-1010#show ncdp status = ncdp switch information ==== enabled ============== revertive root clock source priority: 10 root clock source stratum level: 2 root clock source prs id: 0 stratum level of root switch: 3 clocking root address: 4700000000000001000200885000309409F6BA01 hop count: 2 root path cost: 20 root port: 2 <ATM0/1/0> max age: 20 hello time: 500 ... LS-1010#

To force the NCDP network application to change the network clock source and distribution paths, you unplug the external clock input cable. At this time, the external clock source in the MGX-8850 is declared bad. See Example 10-41.

Example 10-41. Displaying NCDP Clock Sources

m8850-7a.7.PXM.a > dspncdpclksrcs PortId Best clk src Priority Stratum level Prs id Health 7.35 (t1) No 10 2 0(external) Bad 255.255 Yes 128 3 255(internal) unknown m8850-7a.7.PXM.a >

The next priority network clock source should become clock root, as shown in Example 10-42.

Example 10-42. Displaying NCDP Status and Root Clock Source

m8950-7b.7.PXM.a > dspncdp Distribution Mode : ncdp Node stratum level : 3 Max network diameter : 20 Hello time interval : 500 Holddown time interval : 500 Topology change time interval : 500 Root Clock Source : 255.255 Root Stratum Level : 3 Root Priority : 100 Last clk src change time : Feb 20 2002 14:38:59 Last clk src change reason : Root Aged Out m8950-7b.7.PXM.a >

Because of the fact that the BPX controller card where the BPX clock inputs reside does not currently house a VSI slave, the SES-BPX-based node does not currently support NCDP. However, AutoRoute provides automatic clock distribution.