Hierarchical PNNI Configuration

This section covers the migration of a single peer group (SPG) PNNI network into a hierarchical multiple peer group (MPG) network.

There are two fundamental MPG migration modelsadding a lower PNNI level, and adding a higher PNNI level:

• Adding a lower PNNI level This growth model consists of replacing a lowest-level physical node in an SPG with a logical PNNI node and moving the lowest level down the hierarchy. It can be used as the SPG grows or when you add new lower-level nodes to the PNNI network. The original SPG level is higher than the MPG lowest level.

• Adding a higher PNNI level This growth model is more often used to join unpeered or separate PNNI networks forming two different peer groups that meet as logical group nodes (LGNs) at a higher hierarchical level. The original SPG level is the same as the lowest MPG level.

This chapter goes through a complete example of MPG migration, following the model of adding a lower PNNI level. Starting from the SPG PNNI network built in Chapter 10, you will configure a new lowest hierarchical plane at level 80. As shown in Figure 11-1, one of the main enablers of this migration is the addressing scheme you choose, stressing the importance of a planned and thorough addressing plan.

Figure 11-1. PNNI Node's AESAs for Hierarchical PNNI

In Figure 11-1, you can see that level 64 has a common peer group ID (PGID) among all nodes. That is why the initial network is an SPG. However, the lower level 80 has two different PGIDs and thus two different regions. The MGX-8850 and MGX-8950 PNNI nodes are within a peer group called PG-A, and the BPX-SES and LS1010 PNNI nodes are in a different peer group called PG-B.

Initial SPG PNNI Network

The final state of the PNNI network from Chapter 10 is the initial stage of the MPG migration. The original PNNI network is shown in Figure 11-2.

Figure 11-2. Initial SPG PNNI Network

In Figure 11-2, you can see that the original state has a level 64 SPG PNNI network with four PNNI nodes. These PNNI nodes are physical nodes that are interconnected by lowest-level horizontal PNNI links in twoWayInside state.

Adding a Lower Level to the First Node in Peer Group A

The first step in the MPG configuration is to move down the hierarchy in the MGX-8850 PNNI node to the lower level 80 and replace the level 64 PNNI node with a logical PNNI node. This logical node is an LGN, as shown in Figure 11-3.

Figure 11-3. Moving the First Node Down the Hierarchy

From a configuration perspective, before you change the PNNI configuration, you need to administratively down the PNNI node. This step does not affect existing calls, but it prevents new switched connections from being successfully established. After the PNNI node is administratively down, the lowest-level PNNI node (node index 1) is configured with the new level of 80, the new node ID, and the new peer group ID. In addition, a non-null election priority is configured. Example 11-1 shows these configuration steps.

Example 11-1. Lowering the MGX-8850 PNNI Node Level

 m8850-7a.7.PXM.a > cnfpnni-node 1 -enable false m8850-7a.7.PXM.a > cnfpnni-node 1 -level 80 m8850-7a.7.PXM.a > cnfpnni-node 1 -nodeId   80:160:47.000000000000010002008850.00309409f6ba.01 m8850-7a.7.PXM.a > cnfpnni-node 1 -pgId 80:47.000000000000010002000000 m8850-7a.7.PXM.a > cnfpnni-election 1 -priority 50 

Last, a logical PNNI node at level 64 is created, and the two PNNI nodes are administratively upped. See Example 11-2.

Example 11-2. Adding a LGN

 m8850-7a.7.PXM.a > addpnni-node 64 Get MAC Address from ID PROM NV...OK: 00 30 94 09 F6 BA m8850-7a.7.PXM.a > cnfpnni-node 1 -enable true m8850-7a.7.PXM.a > cnfpnni-node 2 -enable true 

NOTE

The higher-level PNNI node's name is formed by taking the lowest-level PNNI node's name and appending a dash and the node index. For example, for a lowest-level PNNI node named m8850-7a, the higher-level node with index 2 is named m8850-7a-02.

The first thing to check is that the PNNI node at level 80 is the peer group leader (PGL) of the LGN at level 64. You do this by checking the PNNI election, as Example 11-3 shows.

Example 11-3. Checking the Peer Group Leadership

 m8850-7a.7.PXM.a > dsppnni-election 1 node index: 1    PGL state......        OperPgl     Init time(sec).......        15    Priority.......            100     Override delay(sec)..        30                                       Re-election time(sec)        15    Pref PGL...............80:160:47.000000000000010002008850.00309409f6ba.01    PGL....................80:160:47.000000000000010002008850.00309409f6ba.01    Active parent node id..64:80:47.000000000000010002000000.00309409f6ba.00 

You can see that it is operational and acting as PGL. It is important to note that 50 priority units were added to the configured 50 to make 100. This is done in PNNI to provide stability for the elected PGL.

The second item you need to look up are the PNNI links. Figure 11-3 shows that each of the two PNNI nodes has two PNNI links. You can check this using the command dsppnni-link, as shown in Example 11-4.

Example 11-4. Using dsppnni-link

 m8850-7a.7.PXM.a > dsppnni-link node index   : 1 Local port id:   16848898          Remote port id:     262912 Local Phy Port Id: 1:1.2:2    Type.      outsideLinkAndUplink     Hello state.......commonOutside    Derive agg...........         0     Intf index...........  16848898    SVC RCC index........         0     Hello pkt RX.........       571                                        Hello pkt TX.........       584    Remote node name.......SES-3a    Remote node id.........64:160:47.000000000000010001008600.00d058ac2828.01    Upnode id..............64:160:47.000000000000010001008600.00d058ac2828.01    Upnode ATM addr........47.000000000000010001008600.00d058ac2828.01    Common peer group id...64:47.00.0000.0000.0001.0000.0000.00 node index   : 1 Local port id:   17569793          Remote port id:   17111041 Local Phy Port Id: 12:1.1:1    Type.      outsideLinkAndUplink     Hello state.......commonOutside    Derive agg...........         0     Intf index...........  17569793    SVC RCC index........         0     Hello pkt RX.........       578 Type <CR> to continue, Q<CR> to stop:                                        Hello pkt TX.........       580    Remote node name.......m8950-7b    Remote node id.........64:160:47.000000000000010002008950.0004c113ba46.01    Upnode id..............64:160:47.000000000000010002008950.0004c113ba46.01    Upnode ATM addr........47.000000000000010002008950.0004c113ba46.01    Common peer group id...64:47.00.0000.0000.0001.0000.0000.00 node index   : 2 Local port id:          1          Remote port id:          1 Local Phy Port Id: n/a    Type.   horizontalLinkToFromLgn     Hello state....... twoWayInside    Derive agg...........         0     Intf index...........         0    SVC RCC index........         1     Hello pkt RX.........         7                                        Hello pkt TX.........         8    Remote node name.......SES-3a    Remote node id.........64:160:47.000000000000010001008600.00d058ac2828.01    Upnode id..............0:0:00.000000000000000000000000.000000000000.00    Upnode ATM addr........00.000000000000000000000000.000000000000.00    Common peer group id...00:00.00.0000.0000.0000.0000.0000.00 node index   : 2 Local port id:          2          Remote port id:          1 Local Phy Port Id: n/a    Type.   horizontalLinkToFromLgn     Hello state....... twoWayInside    Derive agg...........         0     Intf index...........         0    SVC RCC index........         2     Hello pkt RX.........         5                                        Hello pkt TX.........         8    Remote node name.......m8950-7b    Remote node id.........64:160:47.000000000000010002008950.0004c113ba46.01    Upnode id..............0:0:00.000000000000000000000000.000000000000.00    Upnode ATM addr........00.000000000000000000000000.000000000000.00    Common peer group id...00:00.00.0000.0000.0000.0000.0000.00 m8850-7a.7.PXM.a > 

To begin with, we will analyze the links of the PNNI node at the lowest level (level 80), which has node index 1. This PNNI node has two links (which are the physical links) of type outsideLinkAndUplink. One of them has the SES/BPX as a remote node, and the other has the MGX-8950 as a remote node. These links are outside links because the remote nodes are outside the local node's peer group, but they are also uplinks because the remote nodes are at the higher level 64. Hence, the links are of type outsideLinkAndUplink. The hello state of these links is commonOutside, indicating that the node finds a common level of the routing hierarchy and achieves full bidirectional communication with a neighbor node. A switch can advertise links that reach the commonOutside state in PTSEs as uplinks to the upnode.

Second, let's look at the logical links from the highest-level PNNI node, which has a node index of 2. These two links are horizontal links because the peer PNNI node is at the same hierarchical level of 64, but they are not lowest-level. They receive the type horizontal-LinkToFromLgn, indicating that they are horizontal links from a logical group node. These links achieve a twoWayInside state, indicating bidirectional communication. Database summary, PNNI Topology State Element (PTSE) request, PNNI Topology State Packets (PTSPs), and PTSE acknowledgment packets can only be transmitted over links in twoWayInside state. If the link is in twoWayInside state, the local node receives the remote node ID and port ID.

Finally, it's also worth noting that the links from the LGN have a non-null SVC-RCC index. They use SVC-based routing control channels (RCCs). You can see this using the command dsppnni-svcc-rcc, as shown in Example 11-5.

Example 11-5. Using dsppnni-svcc-rcc

 m8850-7a.7.PXM.a > dsppnni-svcc-rcc node index: 2                      svc index: 1    Hello pkt RX........        15     SVCC VPI............         0    Hello pkt TX........        14     SVCC VCI............        66    Hello state............twoWayInside    Remote node id.........64:160:47.000000000000010001008600.00d058ac2828.01    Remote node ATM addr...47.000000000000010001008600.00d058ac2828.01 node index: 2                      svc index: 2    Hello pkt RX........        14     SVCC VPI............        10    Hello pkt TX........        14     SVCC VCI............        37    Hello state............twoWayInside    Remote node id.........64:160:47.000000000000010002008950.0004c113ba46.01    Remote node ATM addr...47.000000000000010002008950.0004c113ba46.01 m8850-7a.7.PXM.a > 

Adding a Lower Level to the Second Node in Peer Group A

The second step in the MPG migration is to lower the hierarchical level of the MGX-8950 PNNI node to level 80 and add its logical PNNI node at level 64, as shown in Figure 11-4. At level 80, the MGX-8950 PNNI node belongs to the same peer group as the MGX-8850 at level 80. That peer group is called PG-A.

Figure 11-4. Moving the Second Node Down the Hierarchy

Using the same procedure, as Example 11-6 shows, you lower the lowest-level node to level 80 in the MGX-8950 and add a logical node at level 64. You also configure the peer group leader election priority so that the MGX-8950 lowest-level node is elected PGL.

Example 11-6. Adding a Lower Level to the MGX-8950 PNNI Node

 m8950-7b.7.PXM.a > cnfpnni-node 1 -enable false m8950-7b.7.PXM.a > cnfpnni-node 1 -level 80 m8950-7b.7.PXM.a > cnfpnni-node 1 -nodeId   80:160:47.000000000000010002008950.0004c113ba46.01 m8950-7b.7.PXM.a > cnfpnni-node 1 -pgId 80:47.000000000000010002000000 m8950-7b.7.PXM.a > cnfpnni-election 1 -priority 150 m8950-7b.7.PXM.a > addpnni-node 64 Get MAC Address from ID PROM NV...OK: 00 04 C1 13 BA 46 m8950-7b.7.PXM.a > cnfpnni-node 1 -enable true m8950-7b.7.PXM.a > cnfpnni-node 2 -enable true 

At this point, the MGX-8950 lowest level is elected PGL (see Example 11-7). This is indicated in Figure 11-4 with a darker node color.

Example 11-7. Displaying PNNI Leadership Election

 m8950-7b.7.PXM.a > dsppnni-election node index: 1    PGL state......        OperPgl     Init time(sec).......        15    Priority.......            200     Override delay(sec)..        30                                       Re-election time(sec)        15    Pref PGL...............80:160:47.000000000000010002008950.0004c113ba46.01    PGL....................80:160:47.000000000000010002008950.0004c113ba46.01    Active parent node id..64:80:47.000000000000010002000000.0004c113ba46.00 node index: 2    PGL state......     OperNotPgl     Init time(sec).......        15    Priority.......              0     Override delay(sec)..        30                                       Re-election time(sec)        15    Pref PGL...............0:0:00.000000000000000000000000.000000000000.00    PGL....................0:0:00.000000000000000000000000.000000000000.00    Active parent node id..0:0:00.000000000000000000000000.000000000000.00 

As with the MGX-8850 PNNI node, the MGX-8950's election priority is increased by 50 the moment it is elected. See Example 11-8. On the MGX-8850, the election priority returns to 50 because it is no longer the PGL.

Example 11-8. Checking the Election Priority

 m8850-7a.7.PXM.a > dsppnni-election node index: 1    PGL state......     OperNotPgl     Init time(sec).......        15    Priority.......             50     Override delay(sec)..        30                                       Re-election time(sec)        15    Pref PGL...............80:160:47.000000000000010002008950.0004c113ba46.01    PGL....................80:160:47.000000000000010002008950.0004c113ba46.01    Active parent node id..0:0:00.000000000000000000000000.000000000000.00 node index: 2    PGL state......       Starting     Init time(sec).......        15    Priority.......              0     Override delay(sec)..        30                                       Re-election time(sec)        15    Pref PGL...............0:0:00.000000000000000000000000.000000000000.00    PGL....................0:0:00.000000000000000000000000.000000000000.00    Active parent node id..0:0:00.000000000000000000000000.000000000000.00 m8850-7a.7.PXM.a > 

It is extremely important to note that the level-64 PNNI LGN runs in the MGX-8950 because it was elected PGL. The PNNI election at level 64 in the MGX-8850 stays in starting state because the MGX-8850 is not PGL and does not run PNNI at level 64. Similarly, PNNI neighbors and links at level 64 are visible only from the PGLthat is, from the MGX-8950. PNNI neighbors and links at level 64 are not visible from the MGX-8850, because it is not PGL.

From a design perspective, it is advisable to configure at least primary and secondary PGLs in a peer group, because a single PGL is a single point of failure. The selection of the PGL node is an important part of designing MPG PNNI networks. PGL functionality uses extra CPU power, so you should avoid PNNI nodes with extra CPU load. These include border nodes and nodes with many signaling links.

Example 11-9 explores the PNNI neighbors seen from the MGX-8950 PNNI node.

Example 11-9. PNNI Neighbors to the MGX-8950 Node

 m8950-7b.7.PXM.a > dsppnni-neighbor node index    : 1 node name     : m8850-7a Remote node id: 80:160:47.000000000000010002008850.00309409f6ba.01 Neighbor state: FULL    Port count..........         1     SVC RCC index.......         0    RX DS pkts..........         3     TX DS pkts..........         2    RX PTSP pkts........        37     TX PTSP pkts........        99    RX PTSE req pkts....         1     TX PTSE req pkts....         1    RX PTSE ack pkts....        49     TX PTSE ack pkts....        11 node index    : 2 node name     : LS-1010 Remote node id: 64:160:47.000000000000010001001010.00503efba601.00 Neighbor state: FULL    Port count..........         1     SVC RCC index.......         2    RX DS pkts..........         2     TX DS pkts..........         3    RX PTSP pkts........         3     TX PTSP pkts........         1    RX PTSE req pkts....         0     TX PTSE req pkts....         0    RX PTSE ack pkts....         1     TX PTSE ack pkts....         3 node index    : 2 node name     : SES-3a Remote node id: 64:160:47.000000000000010001008600.00d058ac2828.01 Neighbor state: FULL    Port count..........         1     SVC RCC index.......         1    RX DS pkts..........         2     TX DS pkts..........         3    RX PTSP pkts........        10     TX PTSP pkts........        10    RX PTSE req pkts....         1     TX PTSE req pkts....         2    RX PTSE ack pkts....         4     TX PTSE ack pkts....         3 m8950-7b.7.PXM.a > 

The lowest-level PNNI node index 1 has the MGX-8850 as a PNNI neighbor in FULL state. The remote node ID has a level indicator of 80. The PNNI node index 2 at level 64 has two neighbors in FULL state: the nodes LS-1010 and SES-3a, both with a level indicator of 64. Note that these two neighbors at level 64 use SVC-based RCCs for the hello protocol.

Referring to Figure 11-4, you can verify the PNNI links at both levels.

First, you see the PNNI links in node index 1 at level 80. You use the command dsppnni-link, specifying a node index, as shown in Example 11-10.

Example 11-10. Specifying a Node Index with dsppnni-link

 m8950-7b.7.PXM.a > dsppnni-link 1 node index   : 1 Local port id:   16848897          Remote port id: 2148532224 Local Phy Port Id: 1:1.1:1    Type.      outsideLinkAndUplink     Hello state.......commonOutside    Derive agg...........         0     Intf index...........  16848897    SVC RCC index........         0     Hello pkt RX.........      4356                                        Hello pkt TX.........      3646    Remote node id.........64:160:47.000000000000010001001010.00503efba601.00    Upnode id..............64:160:47.000000000000010001001010.00503efba601.00    Upnode ATM addr........47.000000000000010001001010.00503efba601.01    Common peer group id...64:47.00.0000.0000.0001.0000.0000.00 node index   : 1 Local port id:   17111041          Remote port id:   17569793 Local Phy Port Id: 5:1.1:1    Type. lowestLevelHorizontalLink     Hello state....... twoWayInside    Derive agg...........         0     Intf index...........  17111041    SVC RCC index........         0     Hello pkt RX.........       677                                        Hello pkt TX.........       749    Remote node name.......m8850-7a    Remote node id.........80:160:47.000000000000010002008850.00309409f6ba.01    Upnode id..............0:0:00.000000000000000000000000.000000000000.00    Upnode ATM addr........00.000000000000000000000000.000000000000.00    Common peer group id...00:00.00.0000.0000.0000.0000.0000.00 m8950-7b.7.PXM.a > 

You see two links: a lowestLevelHorizontalLink toward the level 80 MGX-8850 neighbor, and an outsideLinkAndUplink toward the level 64 LS-1010.

Second, there are also two PNNI logical links from the level 64 logical group node. These are shown in Example 11-11.

Example 11-11. PNNI Links from the Level 64 Logical Group Node

 m8950-7b.7.PXM.a > dsppnni-link 2 node index   : 2 Local port id:          1          Remote port id:          1 Local Phy Port Id: n/a    Type.   horizontalLinkToFromLgn     Hello state....... twoWayInside    Derive agg...........         0     Intf index...........         0    SVC RCC index........         1     Hello pkt RX.........        11                                        Hello pkt TX.........        13    Remote node name.......SES-3a    Remote node id.........64:160:47.000000000000010001008600.00d058ac2828.01    Upnode id..............0:0:00.000000000000000000000000.000000000000.00    Upnode ATM addr........00.000000000000000000000000.000000000000.00    Common peer group id...00:00.00.0000.0000.0000.0000.0000.00 node index   : 2 Local port id:          2          Remote port id:   33476608 Local Phy Port Id: n/a    Type.   horizontalLinkToFromLgn     Hello state....... twoWayInside    Derive agg...........         0     Intf index...........         0    SVC RCC index........         2     Hello pkt RX.........        12                                        Hello pkt TX.........        14    Remote node name.......LS-1010    Remote node id.........64:160:47.000000000000010001001010.00503efba601.00    Upnode id..............0:0:00.000000000000000000000000.000000000000.00    Upnode ATM addr........00.000000000000000000000000.000000000000.00    Common peer group id...00:00.00.0000.0000.0000.0000.0000.00 m8950-7b.7.PXM.a > 

Node index 2 has two horizontalLinkToFromLgn logical links in twoWayInside state toward the level 64 PNNI nodes SES-3a and LS-1010. At this point, the peer group PG-A is configured and operational.

Adding a Lower Level to the Third Node in Peer Group B

The third step in the PNNI hierarchical configuration is to add a lower level to the SES-BPX PNNI node. At level 80, this PNNI node is in a different peer group than the previous two PNNI nodes. This peer group is called PG-B, as shown in Figure 11-5.

Figure 11-5. Moving the Third Node Down the Hierarchy

As with the previous two nodes, the lowest level is lowered to level 80. The peer group ID at level 80 is different from the previous two PNNI nodes, so this level 80 PNNI node is in a different peer group. A non-null election priority is also configured for the lowest-level node. You can see the configuration in Example 11-12.

Example 11-12. Adding a Lower Level to the BPX-SES PNNI Node

 SES-3a.1.PXM.a > cnfpnni-node 1 -enable false SES-3a.1.PXM.a > cnfpnni-node 1 -level 80 SES-3a.1.PXM.a > cnfpnni-node 1 -pgId 80:47.000000000000010001000000 SES-3a.1.PXM.a > cnfpnni-node 1 -nodeId   80:160:47.000000000000010001008600.00d058ac2828.01 SES-3a.1.PXM.a > cnfpnni-election 1 -priority 1 SES-3a.1.PXM.a > addpnni-node 64 SES-3a.1.PXM.a > cnfpnni-node 1 -enable true SES-3a.1.PXM.a > cnfpnni-node 2 -enable true SES-3a.1.PXM.a > 

The SES PNNI node is elected peer group leader with a priority of 51 (the configured value of 1 plus 50 to provide hysteresis).

It is important to note that at level 80 (the lowest level), the PNNI node does not have any PNNI neighbors. The other two nodes at level 80 are in a different peer group. You can see this with the command dsppnni-neighbor, as shown in Example 11-13.

Example 11-13. Displaying PNNI Neighbors Using dsppnni-neighbor

 SES-3a.1.PXM.a > dsppnni-neighbor node index    : 2 node name     : m8950-7b-02 Remote node id: 64:80:47.000000000000010002000000.0004c113ba46.00 Neighbor state: FULL    Port count..........         1     SVC RCC index.......         1    RX DS pkts..........         2     TX DS pkts..........         3    RX PTSP pkts........         8     TX PTSP pkts........         6    RX PTSE req pkts....         1     TX PTSE req pkts....         1    RX PTSE ack pkts....         3     TX PTSE ack pkts....         1 node index    : 2 node name     : LS-1010 Remote node id: 64:160:47.000000000000010001001010.00503efba601.00 Neighbor state: FULL    Port count..........         1     SVC RCC index.......         2    RX DS pkts..........         2     TX DS pkts..........         3    RX PTSP pkts........         1     TX PTSP pkts........         1    RX PTSE req pkts....         0     TX PTSE req pkts....         0    RX PTSE ack pkts....         1     TX PTSE ack pkts....         1 SES-3a.1.PXM.a > 

Note that the first neighbor (m8950-7b-02) is an LGN and the second neighbor is a physical node.

The link type and status of the SES PNNI nodes correspond to the ones the MGX-8850 had in the first configuration step. The lowest-level PNNI node has two outsideLinkAndUplink links in commonOutside state, and the higher-level node has two horizontalLinkToFromLgn links in twoWayInside state.

In Figure 11-5, a dotted arc between two links from a level-80 node means that it is the same link.

Adding a Lower Level to the Fourth Node

The fourth and final step in the hierarchical configuration involves adding a lower level to the Cisco IOS-based PNNI node. Figure 11-6 shows the end result of this step and the complete exercise.

Figure 11-6. Final MPG PNNI Network

As Example 11-14 shows, when using a different set of commands, you need to execute the same tasks to create a lower level in the Cisco IOS Software-based PNNI node. You need to administratively down the PNNI node, lower the level to 80, add a parent PNNI node at level 64, and enable both PNNI nodes.

Example 11-14. Adding a Lower PNNI Level to the IOS PNNI Node

 LS-1010#conf t Enter configuration commands, one per line.  End with CNTL/Z. LS-1010(config)#atm router pnni LS-1010(config-atm-router)#node 1 disable LS-1010(config-pnni-node)#node 1 level 80 LS-1010(config-pnni-node)#node 2 level 64 LS-1010(config-pnni-node)#node 1 LS-1010(config-pnni-node)#parent 2 LS-1010(config-pnni-node)#node 1 enable LS-1010(config-pnni-node)#node 2 enable 

Because you did not configure an election priority in the lowest-level node, the SES-based node is still PGL. The higher-level PNNI node is not running in the Cisco IOS Software-based PNNI node. See Example 11-15.

Example 11-15. Displaying PNNI Node Details

 LS-1010#show atm pnni local-node PNNI node 1 is enabled and running   Node name: LS-1010   System address          47.000000000000010001001010.00503EFBA601.01   Node ID          80:160:47.000000000000010001001010.00503EFBA601.00   Peer group ID        80:47.0000.0000.0000.0100.0100.0000   Level 80, Priority 0 0, No. of interfaces 2, No. of neighbors 1   Parent Node Index: 2   Node Allows Transit Calls   Node Representation: simple <snip> PNNI node 2 is enabled and not running   Node name: LS-1010.2.64   System address          47.000000000000010001001010.00503EFBA601.02   Node ID           64:80:47.000000000000010001000000.00503EFBA601.00   Peer group ID        64:47.0000.0000.0000.0100.0000.0000   Level 64, Priority 0 0, No. of interfaces 0, No. of neighbors 0   Parent Node Index: NONE   Node Allows Transit Calls   Node Representation: simple <snip> 

You can see in Example 11-16 that the SES-3a PNNI node is still PGL.

Example 11-16. Checking the PNNI Election Priority

 LS-1010#show atm pnni election PGL Status.............: Not PGL Preferred PGL..........: (9) SES-3a Preferred PGL Priority.: 51 Active PGL.............: (9) SES-3a Active PGL Priority....: 51 Active PGL For.........: 00:02:27 Current FSM State......: PGLE Operating: Not PGL Last FSM State.........: PGLE Calculating Last FSM Event.........: Preferred PGL Is Not Self Configured Priority....: 0 Advertised Priority....: 0 Conf. Parent Node Index: NONE PGL Init Interval......: 15 secs Search Peer Interval...: 75 secs Re-election Interval...: 15 secs Override Delay.........: 30 secs LS-1010# 

This is the final stage in the hierarchical level. You have achieved hierarchical abstraction. Figure 11-7 shows the topology picture that the BPX-SES PNNI node hasthat is, the PNNI network as seen from peer group PG-B.

Figure 11-7. Hierarchical Abstraction

The BPX-SES PNNI node has one PNNI neighbor at level 80 (LS-1010) and one neighbor at level 64 (MGX-8950-02), as shown in Figures 11-6 and 11-7 as well as Example 11-17.

Example 11-17. Displaying SES-BPX Node's PNNI Neighbors

 SES-3a.1.PXM.a > dsppnni-neighbor node index    : 1 node name     : LS-1010 Remote node id: 80:160:47.000000000000010001001010.00503efba601.00 Neighbor state: FULL    Port count..........         1     SVC RCC index.......         0    RX DS pkts..........         2     TX DS pkts..........         2    RX PTSP pkts........         2     TX PTSP pkts........         9    RX PTSE req pkts....         1     TX PTSE req pkts....         1    RX PTSE ack pkts....         2     TX PTSE ack pkts....         1 node index    : 2 node name     : m8950-7b-02 Remote node id: 64:80:47.000000000000010002000000.0004c113ba46.00 Neighbor state: FULL    Port count..........         1     SVC RCC index.......         1    RX DS pkts..........         2     TX DS pkts..........         3    RX PTSP pkts........        13     TX PTSP pkts........        11    RX PTSE req pkts....         1     TX PTSE req pkts....         1    RX PTSE ack pkts....         5     TX PTSE ack pkts....         3 SES-3a.1.PXM.a > 

Each node at the lowest level sees four PNNI nodes: two lowest-level nodes, one upnode at the higher level, and one upnode's neighbor.

All the PNNI nodes at level 80 have two links: one link of type lowestLevelHorizontal-Link to the PNNI neighbor within the peer group, and a second link of type outsideLink-AndUpLink to the other peer group's LGN.

At level 64, both LGNs have only one PNNI link. This one PNNI link is a horizontalLink-ToFromLgn in twoWayInside state. The following command in Example 11-18 shows the PNNI links at the highest-level node of index 2.

Example 11-18. Displaying PNNI Links at the Highest Level

 SES-3a.1.PXM.a > dsppnni-link 2 node index   : 2 Local port id:          1          Remote port id:          1 Local Phy Port Id: n/a    Type.   horizontalLinkToFromLgn     Hello state....... twoWayInside    Derive agg...........         0     Intf index...........         0    SVC RCC index........         1     Hello pkt RX.........        24                                        Hello pkt TX.........        29    Remote node name.......m8950-7b-02    Remote node id.........64:80:47.000000000000010002000000.0004c113ba46.00    Upnode id..............0:0:00.000000000000000000000000.000000000000.00    Upnode ATM addr........00.000000000000000000000000.000000000000.00    Common peer group id...00:00.00.0000.0000.0000.0000.0000.00 SES-3a.1.PXM.a > 

Because you know the topology at all levels, you know that two physical links at level 80 connect the LGNs at level 64. Those two links are seen as a single logical link at level 64. The reason for this is that the two links at the lower level have the same aggregation token, so they are aggregated into a single logical link. The aggregation token defaults to 0. Thus, the default behavior is to aggregate links into a single logical link at a higher hierarchical level (a summary link between peer groups).

You can see the aggregation token in Example 11-19, a 32-bit number used for link aggregation, using the command dsppnni-intf. You can modify it with the command cnfpnni-intf. The aggregation token identifies uplinks to be aggregated into a single link such that uplinks with the same token are the single link.

Example 11-19. Displaying the PNNI Link Aggregation Token

 m8950-7b.7.PXM.a > dsppnni-intf 1:1.1:1 Physical port id: 1:1.1:1          Logical port id:   16848897    Aggr token..........         0     AW-NRTVBR...........      5040    AW-CBR..............      5040     AW-ABR..............      5040    AW-RTVBR............      5040     AW-UBR..............      5040 m8950-7b.7.PXM.a > 

With link aggregation, a single link represents multiple links between child peer groups (PGs) the same way that with node aggregation a simple LGN represents the complete child PG. Both processes are summarized under the concept of PNNI topology aggregation, which gives the PNNI protocol great scalability.

Link aggregation is shown in Figure 11-8.

Figure 11-8. Link Aggregation Example

With link aggregation, metrics (additive parameters) from individual links are added to determine the metric of the aggregated link. The worst attribute (nonadditive parameters) from individual links becomes the attribute of the aggregated link.

Abstraction Achieved

As pointed out earlier, you have achieved hierarchical abstraction. Many display commands have proven the multiple-level concept. This section shows some more commands to wrap up this idea.

You use the same aesa_ping command used in Chapter 10 in the "PNNI Network Verification" section with the same source PNNI node and AESA destination. See Example 11-20. The difference is that, in Chapter 10, the PNNI network was an SPG network, and now it is an MPG network.

Example 11-20. Using the Command aesa_ping

 m8950-7b.7.PXM.a > aesa_ping 47.000000000000010001008600.00d058ac2828.01 Ping Got CLI message, index=0 PING: from PNNI - SOURCE ROUTE DTL    1 : Number of (Node/port)elements    1 DTL 1:NODE 1: :80:160:71:0:0::2:0:137:80:  Port 1:16848897 DTL    2 : Number of (Node/port)elements    2 DTL 2:NODE 1: :64:80:71:0:0::2:0:0:0:  Port 1:0 DTL 2:NODE 2: :64:80:71:0:0::1:0:0:0:  Port 2:0 Port List : no of ports =    1 Port ID    1:16848897 m8950-7b.7.PXM.a > 

The setup message has a designated transit list (DTL) stack. This is because, given the hierarchical topology aggregation, topology information is summarized outside the peer group.

Table 11-1 summarizes the nodes listed in the two DTLs. You can compare it to Table 10-2 in Chapter 10.

Table 11-1. PNNI Node IDs in the aesa_ping Path for MPG

DTL	Node	PNNI Node ID	Node
1	Node 1	80:160:47.0000...02008950...	MGX-8950
2	Node 1	64:80:47.0000...02000000...	MGX-8950-02
2	Node 2	64:80:47.0000...01000000...	BPX-8600-02

DTL 1 shows the nodes listed at level 80. On the other hand, DTL 2 lists the nodes at level 64, which are the two LGNs at the highest level.

Another useful command is dsppnni-path, which displays the precalculated routes to a specified node as Example 11-21 shows. You use this command to see the routes to all nodes for the administrative weight parameter for the CBR service type.

Example 11-21. Using the Command dsppnni-path for AW with CBR

 m8950-7b.7.PXM.a > dsppnni-path aw cbr node #/PortId   node id                                            node name --------------- -------------------------------------------------- ---------- D  2/         0 80:160:47.000000000000010002008850.00309409f6ba.01 m8850-7a S  1/  17111041 80:160:47.000000000000010002008950.0004c113ba46.01 m8950-7b node #/PortId   node id                                            node name --------------- -------------------------------------------------- ---------- D  5/         0 64:80:47.000000000000010001000000.00d058ac2828.00  SES-3a-02    7/         0 64:80:47.000000000000010002000000.0004c113ba46.00  m8950-7b-02 S  1/  16848897 80:160:47.000000000000010002008950.0004c113ba46.01 m8950-7b m8950-7b.7.PXM.a > 

You can see in Example 11-22 that from the MGX-8950 to the MGX-8850 is a path at the lowest level 80 across physical nodes. However, the routes to the node SES-3a-02 need to go across the level 64 MGX-8950-02 node. If you change the election priority of the nodes in PG-A using the command cnfpnni-election so that the MGX-8850 is elected PGL, the output of the command dsppnni-path changes to show the MGX-8850-02 node at level 64.

Example 11-22. Using the Command dsppnni-path

 m8950-7b.7.PXM.a > dsppnni-path aw cbr node #/PortId   node id                                            node name --------------- -------------------------------------------------- ---------- D  2/         0 80:160:47.000000000000010002008850.00309409f6ba.01 m8850-7a S  1/  17111041 80:160:47.000000000000010002008950.0004c113ba46.01 m8950-7b node #/PortId   node id                                            node name --------------- -------------------------------------------------- ---------- D  5/         0 64:80:47.000000000000010001000000.00d058ac2828.00  SES-3a-02    6/         0 64:80:47.000000000000010002000000.00309409f6ba.00  m8850-7a-02 S  1/  16848897 80:160:47.000000000000010002008950.0004c113ba46.01 m8950-7b m8950-7b.7.PXM.a >