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Management Communications Examples for TCX1000 Linear Multi-Span Networks

 

This sections describes management communications examples for linear multi-span networks. It focuses on network examples and describes how each device in the example handles management communications.

Summary of Deployment Rules for TCX1000-RDM20 and TCX1000-ILA

Here are the hard rules to follow when deploying TCX1000 devices in your optical network:

  1. Each TCX1000-RDM20 and TCX1000-ILA must have redundant paths for management communications with the proNX Optical Director. See, Rule 1: Before Deploying Identify Redundant Paths for Management Communications to Each TCX1000 Device in Deployment Rules for TCX1000 Management Communications.

  2. Keep Layer 2 and Layer 3 management networks together and segregated from other L2/L3 IP subnets. See, Rule 2: Keep Layer 2 and Layer 3 Management Networks Together and Segregated From Other L2/L3 IP Subnets in Deployment Rules for TCX1000 Management Communications.

  3. You must determine whether a TCX1000-RDM20 needs to have OSC forwarding enabled on it and configure the feature before you deploy the TCX1000-RDM20. See, Rule 3: Configure OSC Forwarding on TCX1000-RDM20 Before Deploying in Deployment Rules for TCX1000 Management Communications.

  4. Configure IP set up before deploying TCX1000 devices. See Rule 4: Configure IP Management Before Deploying TCX1000 Devices in Deployment Rules for TCX1000 Management Communications.

  5. Switches that connect to the TCX Series devices to your DCN HA must participate in RSTP to prevent Layer 2 network loops and must be compatible with the IEEE 802.1w RTSP protocol. Both the TCX1000-RDM20 and TCX1000-ILA are compatible with the protocol. See, Rule 5: RSTP Deployment Rules for TCX1000 Devices.

Linear Multi-Span Network: Example 1

Figure 1 shows a linear multi-span network that includes four sites: A, B, C, D.

Looking at our rules for segregating L2/L3 subnets, we can see that each site is on a different IP subnet:

  • At site A, TCX1000-RDM20-a is on IP subnet A.1

  • At site B, TCX1000-RDM20-b is on IP subnet and B.1 and TCX1000-RDM20-c is on IP subnet B.2

  • At site C, TCX1000-RDM20-d is on IP subnet C.1 and TCX1000-RDM20-e is on IP subnet C.2

  • At site D, TCX1000-RDM20-f is on IP subnet D.1

Therefore, we must segregate the L2/L3 networks by fronting them with a L2 switch connected to the DCN ports on each TCX1000-RDM20 in the network. In this example, proNX Optical Director management communications are always sent over the DCN network to the TCX1000 devices.

Figure 1: Direct Connect Linear Multi-Span Network: Example 1
Direct Connect Linear Multi-Span Network:
Example 1
Note

Due to the multiple IP subnets used in this network, OSC forwarding could never be used for management communications. Therefore, we can leave the default setting for OSC forwarding, which is off, on all TCX1000-RDM20s in this network.

In this example, we have clearly kept together the DCN HA L2 subnet and separated each L3 subnet between the sites by disabling OSC forwarding on each device and we have redundant management communications to each TCX 1000 over the DCN HA as required. This example meets all the rules required for this network. It uses quite a few Layer 2 switches but is simple way to deploy a linear multi-span network.

In summary, because all sites in this example are different L2/L3 subnets, all TCX1000-RDM20s in the example use only their dual-DCN ports for communicating management messages.

Best Practice

Figure 1 uses all the best practice guidelines for redundant management communications, L2/L3 subneting and DCN HA design.

Linear Multi-Span Network: Example 2

Figure 2 shows a linear multi-span network that includes four sites: A, B, C, D:

  • At site A, TCX1000-RDM20-a is on IP subnet Z.1

  • At site B, TCX1000-RDM20-b is on IP subnet and Z.2 and TCX1000-RDM20-c is on IP subnet Z.3

  • At site C, TCX1000-RDM20-d is on IP subnet Z.4 and TCX1000-RDM20-e is on IP subnet Z.5

  • At site D, TCX1000-RDM20-f is on IP subnet Z.6

Figure 2: Direct Connect Linear Multi-Span Network: Example 2
Direct Connect Linear Multi-Span Network:
Example 2

All sites in this example are on the Z IP subnet so we do not need to segregate L2/L3 subnets and, following our best practices, each TCX1000 device to an external Layer 2 RSTP-enabled switch for management communications to go over the DCN ports of the TCX1000-RDM20s.

In addition, because this network is all on one IP subnet, we can enable OSC forwarding on the TCX1000-RDM20s if we wanted to. However, there is no need to with the redundant DCN connections.

In summary, all TCX1000-RDM20s in this example use their dual-DCN ports and their Line ports to communicate management messages.

Best Practice

Figure 2 uses all the best practice guidelines for redundant management communications, Layer 2 and Layer 3 subneting and DCN HA design.

This network complies with all of our deployment rules. We have redundant management communications to each TCX1000 device and we have to interactions with L2/L3 segregation because all devices are on the same L2/L3 subnet.

Linear Multi-Span Network – Dual Homed: Example 1

Figure 3 shows a linear multi-span network that includes four sites: A, B, C, D:

  • At site A, TCX1000-RDM20-a is on IP subnet Z.1

  • At site B, TCX1000-RDM20-b is on IP subnet and Z.2 and TCX1000-RDM20-c is on IP subnet Z.3

  • At site C, TCX1000-RDM20-d is on IP subnet Z.4 and TCX1000-RDM20-e is on IP subnet Z.5

  • At site D, TCX1000-RDM20-f is on IP subnet Z.6

All sites in this example are on the Z IP subnet so we not need to segregate L2/L3 subnets. This also tells us that we can manage communication messages to remotely connected devices over the Line ports of TCX1000-RDM20s in the network.

Note

You must enable OSC forwarding on the device before deploying it.

Figure 3: Linear Multi-Span Network – Dual Homed: Example 1
Linear Multi-Span Network –
Dual Homed: Example 1

Between the two TCX1000-RDM20s at sites B and C, there are two connections:

  • The optical line shows the pass-through channels connected between the two TCX1000-RDM20s.

  • The black line shows the DCN ports daisy-chained between the two TCX1000-RDM20s for management communications.

Let us look at how redundant management communications work for each TCX1000 device in Figure 3:

  • Looking at our redundant path rules, we can see that TCX1000-RDM20-a and TCX1000-RDM20-f at sites A and D respectively, are directly connected to the DCN through Layer 2 switches and therefore can communicate management messages over their DCN ports. However, we can also see in Figure 3, that the TCX1000-RDM20s at sites A and D are responsible for providing management communications over their line ports to the TCX1000-RDM20s at sites B and C respectively and therefore, OSC forwarding must be enabled on the TCX1000-RDM20s at sites A, B, C and D so that they can exchange management messages over their Line ports.

  • Looking at our redundant path rules for management communications for the TCX1000-RDM20s at sites B and C, we have already established that the first path is receiving management messages over their Line ports from the TCX1000 devices at site A or site D.

    The second path for remote management communications for the TCX1000-RDM20s at sites B and C is enabled by daisy chaining the DCN ports on the TCX1000-RDM20s at these sites.

    If we daisy DCN ports between TCX1000-RDM20-b and TCX1000-RDM20-c at site B:

    • Management communications for TCX1000-RDM20-b occur over either the line port from site A, or over the DCN port from TCX1000-RDM20-c, which receives management communications from site C.

    • Management communications for TCX1000-RDM20-c occur over either the Line port from site C, or over the DCN port from TCX1000-RDM20-b, which receives management communications from site A.

    If we daisy the DCN ports between TCX1000-RDM20-d and TCX1000-RDM20-e at site C:

    • Management communications for TCX1000-RDM20-d occur over either the Line port from site B, or over the DCN ports from TCX1000-RDM20-e, which receives management communications from site D.

    • Management communications for TCX1000-RDM20-e occur over either the Line port from site D, or over the DCN ports from TCX1000-RDM20-d, which receives management communications from site B.

This example uses fewer switches and complies with all of our management communication deployment rules. We have redundant paths for management communications to each TCX1000 device in the network. The network is on a single IP subnet so we do not worry about segregating any L2/L3 subnets.

In summary, all TCX1000-RDM20s in this example have redundant paths for management communications either through their DCN ports or Line ports and we have met all of our other deployment rule requirements.

Best Practice

Figure 3 uses all the best practice guidelines for redundant management communications at sites A and D, Layer 2 and Layer 3 subneting and DCN HA design.

Note

Although the TCX1000-RDM20s at sites B and C have redundant management communication paths, they are not connected to the DCN HA through external Layer 2 switch, which is not the best practice method for management communications.

Linear Multi-Span Network – Dual Homed: Example 2

The example network deployment in Figure 4 shows a linear multi-span network that includes four sites: A, B, C, D:

  • At site A, TCX1000-RDM20-a is on IP subnet Z.1

  • At site B, TCX1000-ILA-a is on IP subnet and Z.2

  • At site C, TCX1000-RDM20-b is on IP subnet Z.3 and TCX1000-RDM20-c is on IP subnet Z.4

  • At site D, TCX1000-RDM20-d is on IP subnet Z.5

All TCX1000 devices in the networks are on the same L2/L3 subnet so we do not need to worry about our L2/L3 segregation rule.

Figure 4: Linear Multi-Span Network – Dual Homed: Example 2
Linear Multi-Span Network –
Dual Homed: Example 2

Between the two TCX1000-RDM20s at sites C, there are two connections:

  • The optical line shows the pass-through channels connected between the two TCX1000-RDM20s.

  • The black line shows the DCN ports daisy-chained between the two TCX1000-RDM20s for management communications.

Looking at our rules for redundant paths for management communications in Figure 4, we can see that TCX1000-RDM20-a and TCX1000-RDM20-d at sites A and D respectively, are directly connected to the DCN through a single connection and can therefore communicate directly with the proNX Optical Director over the DCN. However, sites A and D each have only a single connection to the DCN and they require two paths for redundant management communications.

In addition, sites B and C have no direct access to the DCN. At site B we have a TCX1000-ILA, which is using it Line ports to send management communications.

At site C, there is no DCN access and therefore the TCX1000 devices at site C cannot send management communications over their DCN ports and instead must send them over their Line ports.

Table 1 summarizes the management communications and methods for each TCX1000 device shown in Figure 4.

Table 1: Summary of Management Communications

Site

Device

OSC Forwarding Enabled

Management Communications for proNX Optical Director

A

TCX1000-RDM20-a

Yes

Uses a single connection to the DCN port and as the secondary path uses its Line port to exchange management messages with the TCX1000-ILA-a at site B.

B

TCX1000-ILA-a

N/A

Uses its Line A port to exchange management messages with site A and uses its Line B port to exchange management messages with site C.

C

TCX1000-RDM20-b

Yes

Uses its Line port to exchange management messages with site B and has its DCN port daisy-chained to the DCN port of TCX1000-RDM20-c for management communications from site D.

TCX1000-RDM20-c

Yes

Uses its Line port to exchange management messages with TCX1000-RDM20-d at site D and has its DCN port daisy-chained to the DCN port of TCX1000-RDM20-b to receive management communications from site B.

D

TCX1000-RDM20-d

Yes

Uses a single connection to the DCN and as the second path uses its Line port to exchange management messages with the TCX1000-RDM20-c at site C.

In summary, all TCX1000 devices in Figure 4 have redundant paths for management communications either through their Ethernet management ports or their Line ports and we have met all of our other deployment rule requirements.

However, none of the TCX1000 devices in this example use the best practice management communications methods. The TCX1000-RDM20s use a single DCN port and or their Line ports but none of them have dual-DCN connections to the DCN HA. The TCX1000-ILA uses only its Line ports for management communications and not the MGMT port, which is the best method to use.

Linear Multi-Span Network – Dual Homed

The example network deployment inFigure 5 shows a linear multi-span network that includes four sites: A, B, C, D. Looking at our rules for L2/L3 subnets, we can see:

  • At site A, TCX1000-RDM20-a is on IP subnet Z.1

  • At site B, TCX1000-ILA-a is on IP subnet and Z.2

  • At site C, TCX1000-RDM20-b is on IP subnet Z.3 and TCX1000-RDM20-c is on IP subnet Z.4

  • At site D, TCX1000-RDM20-d is on IP subnet D.1

TCX1000-RDM20-d at site D is on a different IP subnet (subnet D) than the other sites in the network, which are all on IP subnet Z. This tells us that we must do several things on TCX1000-RDM20-d:

  1. We need to segregate site D because it is on a different L2/L3 network subnet. This means that all management communications to TCX1000-RDM20-d at site D must are through the dual-DCN ports and the proNX Optical Director must be able to access the cloud at site D through L3 IP communications.

  2. We also need to ensure we do not enable OSC forwarding on the line port of TCX1000-RDM20-d at site D because we do not want to forward management messages from one IP subnet to another since the TCX1000-RDM20 acts as a Layer 2 device in the network.

Figure 5: Linear Multi-Span Network – Dual Homed
Linear Multi-Span Network
– Dual Homed

Between the two TCX1000-RDM20s at sites C, there are two connections:

  • The optical line shows the pass-through channels connected between the two TCX1000-RDM20s.

  • The black line shows the DCN ports daisy-chained between the two TCX1000-RDM20s for management communications.

Looking at our rules for redundant network management communications in Figure 5, we can see that TCX1000-RDM20-a at site A is directly connected to the DCN through a single DCN connection. The secondary path for management communications for TCX1000-RDM20-a is over its line port from the TCX1000-ILA-a at site B, therefore we must enable OSC forwarding on TCX1000-RDM20-a at site A.

At site B we have a TCX1000-ILA, which has no access to the DCN. Line A receives management communications over OSCA from TCX1000-RDM20-a at site A. Line B receives management communications over OSCB from TCX1000-RDM20-b at site C.

At site C, we have TCX1000-RDM20-b and TCX1000-RDM20-c, which each have only a single DCN connection for management communications. The OSCB from the TCX1000-ILA-a at site B serves as the second path for management communications to TCX1000-RDM20-b. However, TCX1000-RDM20-c cannot receive management communications from TCX1000-RDM20-d at site D because it is on a different IP subnet. Therefore, the second path for management communications to TCX1000-RDM20 c is over its DCN port, which must be daisy-chained to the DCN port of TCX1000-RDM20-b.

Table 2 summarizes the management communications and methods for the example network shown in Figure 5.

Table 2: Summary of Management Communications

Site

Device

OSC Forwarding Enabled

Management Communications for proNX Optical Director

A

TCX1000-RDM20-a

Yes

Uses a single connection to the DCN and as the second path uses its Line port to exchange management messages with the TCX1000-ILA-a at site B.

B

TCX1000-ILA-a

N/A

Uses its Line A port to exchange management messages with site A and uses its Line B port to exchange management messages with site C.

C

TCX1000-RDM20-b

Yes

Uses its Line port to exchange management messages with TCX1000-ILA-a at site B and has its DCN port daisy-chained to the DCN port of TCX1000-RDM20-c for management communications to the DCN.

TCX1000-RDM20-c

Yes

Uses a direct DCN connect to the Layer 2 switch DCN and as a second path has its other DCN port daisy-chained to the DCN port on TCX1000-RDM20-b for redundant management communications.

D

TCX1000-RDM20-d

No

All management communications to this device are through the dual-DCN ports on the device to the L2 switch.

In summary, all TCX1000 devices in Figure 4 have redundant paths for management communications either through their Ethernet management ports or their Line ports and we have met all of our other deployment rule requirements.

However, only the TCX1000-RDM20 at site D is using the best practice management communication methods. The TCX1000-RDM20s use a single DCN port and or their Line ports but none of them have dual-DCN connections to the DCN HA. The TCX1000-ILA uses only its Line ports for management communications and not the MGMT port, which is the best method to use.