MultiPop Scenario

The MultiPop scenario illustrates a configuration that involves two POPs: Montreal and Ottawa. This configuration does not provide redundancy. The NIC proxy communicates with the back office host (BackOffice), which in turn communicates with the POP hosts (MontrealHost and OttawaHost). Hosts MontrealHost and OttawaHost support equivalent hosts and agents and manage resolutions in the same way.

When host BackOffice receives a data key from the NIC proxy, the following sequence of events occurs:

1. Host BackOffice forwards requests as follows:

   • If the request is for the Montreal POP, host BackOffice forwards the request to POP host MontrealHost.

   • If the request is for the Ottawa POP, host BackOffice forwards the request to POP host OttawaHost.

2. Delegating tasks to other resolvers as necessary, the resolvers in the POP obtain data values that correspond to the data key request, and return them.

3. The POP host returns the data values to host BackOffice, which returns the value to the NIC proxy.

The scenario shows three realms for this configuration:

• IP

• Shared IP

• DN

Each realm provides a different type of resolution. The following sections provide information about these realms.

Figure 56 illustrates this configuration.

Figure 56: MultiPop Configuration

IP Realm

This realm accommodates the situation in which IP address pools are configured locally on each VR. The resolution process takes a subscriber’s IP address as the key and returns a reference to the SAE managing this subscriber as the value. This realm uses essentially the same resolution process as the ip realm for the OnePop scenario (see OnePop Scenario). However, some of the constraints differ.

The following agents interact with the resolvers in this realm:

• Directory agents montrealPoolVr and ottawaPoolVr collect and publish information that maps IP address pools to VRs. Each agent publishes only the information that is relevant to its POP. You achieve selective publishing by relating an Ottawa scope to the VRs in the Ottawa POP and a Montreal scope to the VRs in the Montreal POP and defining a search filter for the agents to load only the VRs in its POP.

• Directory agent VrSaeId in the back office collects and publishes information that maps VRs to SAEs for both POPs.

When the NIC proxy sends a subscriber’s IP address to host BackOffice, the following sequence of events occurs:

1. Host BackOffice passes the IP address to resolver ip/A1.

2. Resolver ip/A1 obtains an IP pool for the IP address.

3. Resolver ip/A1, based on the value of the IpPool, forwards the request to ip/B1montreal or ip/B1ottawa.

4. Resolver ip/B1montreal or resolver ip/B1ottawa obtains a VR name for this IP pool and returns the VR name to resolver ip/A1.

5. Resolver ip/A1 forwards the VR name to resolver ip/C1.

6. Resolver ip/C1 obtains the SAE identity for this VR and returns the value to resolver ip/A1.

7. Resolver ip/A1 returns the SAE reference to its host.

8. Host BackOffice returns the SAE reference to the NIC proxy.

Figure 57 illustrates the interactions of the NIC components for this realm.

Figure 57: IP Realm for MultiPop Configuration

Shared IP Realm

This realm accommodates the situation in which IP address pools are shared by VRs in the same POP. The realm takes a subscriber’s IP address as the key and returns the corresponding SAE as the value. To see the resolution graph for this realm, see OnePop Scenario.

The following agents interact with resolvers in this realm:

• Directory agents montrealPoolVr and ottawaPoolVr collect and publish information about the mappings of IP address pools to VRs. Each agent publishes only the information that is relevant to its POP.

• SAE plug-in agents montrealIpVr and ottawaIpVr collect and publish information about the mappings of subscriber IP addresses to VRs. Each agent publishes only the information that is relevant to its POP.

• Directory agent VrSaeId in the back office collects and publishes information about the mappings of VRs to SAEs for both POPs.

When the NIC proxy sends a subscriber’s IP address to host BackOffice, the following sequence of events occurs:

1. Host BackOffice passes the IP address to resolver sharedIp/A1.

2. Resolver sharedIp/A1 obtains an IP pool for the IP address.

3. Resolver sharedIp/A1, based on the value of the IP pool, forwards the request to sharedIp/B1montreal or sharedIp/B1ottawa.

4. Resolver sharedIp/B1montreal or resolver sharedIp/B1ottawa obtains a VR name for this IP address and returns the VR name to resolver sharedIp/A1.

5. Resolver sharedIp/A1 forwards the VR name to resolver sharedIp/C1.

6. Resolver sharedIp/C1 obtains the SAE identity for this VR and returns the value to resolver sharedIp/A1.

7. Resolver sharedIp/A1 passes the SAE reference to its host.

8. Host BackOffice returns the SAE reference to the NIC proxy.

Figure 58 illustrates the interactions of the NIC components for this realm.

Figure 58: sharedIP Realm for MultiPop Configuration

DN Realm

The DN realm takes the DN of an access subscriber (an access DN) as the key and returns the corresponding SAE as the value. Figure 59 shows the resolution process for this realm.

Figure 59 shows the resolution graph for this realm.

Figure 59: Resolution Graph for MultiPop dn Realm

The following agents interact with resolvers in this realm:

• Directory agents ottawaEnterprise and montrealEnterprise collect and publish information about the DNs of enterprise subscribers (enterprise DNs). Each agent publishes only the information that is relevant to its POP. You achieve selective publishing by relating an Ottawa service scope to the enterprises in the Ottawa POP and a Montreal service scope to the enterprises in the Montreal POP and defining a search filter for the agents to load only the enterprises in its POP.

• SAE plug-in agents montrealDnVr and ottawaDnVr collect and publish information about the mappings of access DNs to VRs. Each agent publishes only the information that is relevant to its POP.

• Directory agent VrSaeId collects and publishes information about the mappings of VRs to SAEs for both POPs.

When the NIC proxy sends an access DN to host BackOffice, the following sequence of events occurs:

1. Host BackOffice passes the access DN to resolver dn/A1.

2. Resolver dn/A1 obtains an enterprise DN for the access DN.

3. Resolver dn/A1, based on the value of the enterprise DN, forwards the request to dn/B1montreal or dn/B1ottawa.

4. Resolver dn/B1montreal or resolver dn/B1ottawa obtains a VR name for this enterprise DN and returns the VR name to resolver dn/A1.

5. Resolver dn/A1 forwards the VR name to resolver dn/C1.

6. Resolver dn/C1 obtains the SAE reference for this VR and returns the value to resolver dn/A1.

7. Resolver dn/A1 passes the SAE reference to its host.

8. Host BackOffice returns the SAE reference to the NIC proxy.

Figure 60 illustrates the interactions of the NIC components for this realm.

Figure 60: dn Realm for MultiPop Configuration