Cisco ONS 15454 Reference Manual, Release 3.4
Chapter 13, Ethernet Operation

Table Of Contents

Ethernet Operation

13.1 G1000-4 Application

13.1.1 G1000-4 Example

13.1.2 802.3x Flow Control and Frame Buffering

13.1.3 Ethernet Link Integrity Support

13.1.4 Gigabit EtherChannel/802.3ad Link Aggregation

13.2 E Series Application

13.2.1 E Series Multicard and Single-Card EtherSwitch

13.2.2 ONS 15454 E Series and ONS 15327 EtherSwitch Circuit Combinations

13.3 E Series Circuit Configurations

13.3.1 E-Series Circuit Protection

13.3.2 E Series Point-to-Point Ethernet Circuits

13.3.3 E Series Shared Packet Ring Ethernet Circuits

13.3.4 E Series Hub and Spoke Ethernet Circuit Provisioning

13.3.5 E Series Ethernet Manual Cross-Connects

13.4 G1000-4 Circuit Configurations

13.4.1 G1000-4 Point-to-Point Ethernet Circuits

13.4.2 G1000-4 Manual Cross-Connects

13.5 E Series VLAN Support

13.5.1 E Series Q-Tagging (IEEE 802.1Q)

13.5.2 E Series Priority Queuing (IEEE 802.1Q)

13.5.3 E Series VLAN Membership

13.5.4 VLAN Counter

13.6 E Series Spanning Tree (IEEE 802.1D)

13.6.1 E Series Multi-Instance Spanning Tree and VLANs

13.6.2 Spanning Tree on a Circuit-by-Circuit Basis

13.6.3 E Series Spanning Tree Parameters

13.6.4 E Series Spanning Tree Configuration

13.6.5 E Series Spanning Tree Map

13.7 G1000-4 Performance and Maintenance Screens

13.7.1 G1000-4 Ethernet Performance Screen

13.7.2 G1000-4 Ethernet Maintenance Screen

13.7.3 E-Series Ethernet Performance Screen

13.7.4 E-Series Ethernet Maintenance Screen

13.8 Remote Monitoring Specification Alarm Thresholds


Ethernet Operation


The Cisco ONS 15454 integrates Ethernet into a SONET time-division multiplexing (TDM) platform. The ONS 15454 supports both E series Ethernet cards and the G series Ethernet card. For more information on Ethernet cards, see Chapter 5, "Ethernet Cards."

Chapter topics include:

G1000-4 Application

E Series Application

E Series Circuit Configurations

G1000-4 Circuit Configurations

E Series VLAN Support

E Series Spanning Tree (IEEE 802.1D)

G1000-4 Performance and Maintenance Screens

13.1 G1000-4 Application

The G1000-4 card reliably transports Ethernet and IP data across a SONET backbone. The G1000-4 card maps up to four gigabit Ethernet interfaces onto a SONET transport network. A single card provides scalable and provisionable transport bandwidth at the signal levels up to STS-48c per card. The card provides line rate forwarding for all Ethernet frames (unicast, multicast, and broadcast) and can be configured to support Jumbo frames (defined as a maximum of 10,000 bytes).The G-series card incorporates features optimized for carrier-class applications such as:

High Availability (including hitless (< 50 ms) performance under software upgrades and all types of SONET/SDH equipment protection switches)

Hitless re-provisioning

Support of Gigabit Ethernet traffic at full line rate

Full TL1-based provisioning capability. Refer to the Cisco ONS 15454 and Cisco ONS 15327 TL1 Command Guide for G1000-4 TL1 provisioning commands.

The G1000-4 card allows an Ethernet private line service to be provisioned and managed very much like a traditional SONET or SDH line. G1000-4 card applications include providing carrier-grade Transparent LAN Services (TLS), 100 Mbps Ethernet private line services (when combined with an external 100 Mb Ethernet switch with Gigabit uplinks), and high availability transport for applications such as storage over MAN/WANs.

You can map the four ports on the G1000-4 independently to any combination of STS-1, STS-3c, STS-6c, STS-9c, STS-12c, STS-24c, and STS-48c circuit sizes, provided the sum of the circuit sizes that terminate on a card do not exceed STS-48c.

To support a gigabit Ethernet port at full line rate, an STS circuit with a capacity greater or equal to 1 Gbps (bidirectional 2 Gbps) is needed. An STS-24c is the minimum circuit size that can support a gigabit Ethernet port at full line rate.The G1000-4 supports a maximum of two ports at full line rate.

Ethernet cards may be placed in any of the 12 multipurpose card slots. In most configurations, at least two of the 12 slots need to be reserved for optical trunk cards, such as the OC-192 card. The reserved OC-N slots give the ONS 15454 a practical maximum of ten G1000-4 cards. The G1000-4 card requires the XC10G card to operate. The G1000-4 card is not compatible with XC or XCVT cards.

The G1000-4 transmits and monitors the SONET J1 Path Trace byte in the same manner as ONS 15454 DS-N cards. For more information, refer to the Cisco ONS 15454 Procedure Guide.


Note G-Series encapsulation is standard HDLC framing over SONET/SDH as described in RFC 1622 and RFC 2615 with the PPP protocol field set to the value specified in RFC 1841.


13.1.1 G1000-4 Example

Figure 13-1 shows an example of a G1000-4 application. In this example, data traffic from the Gigabit Ethernet port of a high-end router travels across the ONS 15454 point-to-point circuit to the Gigabit Ethernet port of another high-end router.

Figure 13-1 Data traffic using a G1000-4 point-to-point circuit

The G1000-4 card can carry over a SONET network any layer three protocol that can be encapsulated and transported over Gigabit Ethernet, such as IP or IPX. The data is transmitted on the Gigabit Ethernet fiber into the standard Cisco Gigabit Interface Converter (GBIC) on a G1000-4 card. The G1000-4 card transparently maps Ethernet frames into the SONET payload by multiplexing the payload onto a SONET OC-N card. When the SONET payload reaches the destination node, the process is reversed and the data is transmitted from the standard Cisco GBIC in the destination G1000-4 card onto the Gigabit Ethernet fiber.

The G1000-4 card discards certain types of erroneous Ethernet frames rather than transport them over SONET. Erroneous Ethernet frames include corrupted frames with CRC errors and under-sized frames that do not conform to the minimum 64-byte length Ethernet standard. The G1000-4 card forwards valid frames unmodified over the SONET network. Information in the headers is not affected by the encapsulation and transport. For example, packets with formats that include IEEE 802.1Q information will travel through the process unaffected.

13.1.2 802.3x Flow Control and Frame Buffering

The G1000-4 supports 802.3x flow control and frame buffering to reduce data traffic congestion. To buffer over-subscription, 512 KB of buffer memory is available for the receive and transmit channels on each port. When the buffer memory on the Ethernet port nears capacity, the ONS 15454 uses 802.3x flow control to send back a pause frame to the source at the opposite end of the Gigabit Ethernet connection.

The pause frame instructs that source to stop sending packets for a specific period of time. The sending station waits the requested time before sending more data. Figure 13-1 illustrates pause frames being sent from the ONS 15454s to the sources of the data. The G1000-4 card does not respond to pause frames received from client devices.

This flow-control mechanism matches the sending and receiving device throughput to that of the bandwidth of the STS circuit. For example, a router may transmit to the Gigabit Ethernet port on the G1000-4. This particular data rate may occasionally exceed 622 Mbps, but the ONS 15454 circuit assigned to the G1000-4 port may be only STS-12c (622.08 Mbps). In this example, the ONS 15454 sends out a pause frame and requests that the router delay its transmission for a certain period of time. With a flow control capability combined with the substantial per-port buffering capability, a private line service provisioned at less than full line rate capacity (STS-24c) is nevertheless very efficient because frame loss can be controlled to a large extent.

Some important characteristics of the flow control feature on the G1000-4 include:

The G1000-4 card only supports asymmetric flow control. Flow control frames are sent to the external equipment but no response from the external equipment is necessary or acted upon.

Received flow control frames are quietly discarded. They are not forwarded onto the SONET path, and the G1000-4 card does not respond to the flow control frames.

On the G1000-4 card, you can only enable flow control on a port when auto-negotiation is enabled on the device attached to that port. For more information, Refer to the Provision Path Trace on Circuit Source and Destination Ports (DLP130) in the Cisco ONS 15454 Procedure Guide.

Because of the above characteristics the link auto-negotiation and flow control capability on the attached Ethernet device must be correctly provisioned for successful link auto-negotiation and flow control on the G1000-4. If link auto-negotiation fails, the G1000-4 does not use flow control (default). Without flow control, traffic loss can occur if the input traffic rate is higher than the bandwidth of the circuit for an extended period of time.

13.1.3 Ethernet Link Integrity Support

The G1000-4 supports end-to-end Ethernet link integrity. This capability is integral to providing an Ethernet private line service and correct operation of layer 2 and layer 3 protocols on the attached Ethernet devices at each end. End-to-end Ethernet link integrity essentially means that if any part of the end-to-end path fails the entire path fails. Failure of the entire path is ensured by turning off the transmit lasers at each end of the path. The attached Ethernet devices recognize the disabled transmit laser as a loss of carrier and consequently an inactive link.

Figure 13-2 End-to-end Ethernet link integrity support


Note Some network devices can be configured to ignore a loss of carrier condition. If such a device attaches to a G1000-4 card at one end then alternative techniques (such as use of layer 2 or layer 3 protocol keep alive messages) are required to route traffic around failures. The response time of such alternate techniques is typically much longer than techniques that use link state as indications of an error condition.



Note Enabling or disabling port level flow control on the test set or other Ethernet device attached to the G1000-4 port can affect the transmit (Tx) laser. This can result in unidirectional traffic flow, if flow control is not enabled on the test set or other Ethernet device.


As shown in Figure 13-2, a failure at any point of the path (A, B, C, D or E) causes the G1000-4 card at each end to disable its Tx transmit laser at their ends, which causes the devices at both ends to detect link down. If one of the Ethernet ports is administratively disabled or set in loopback mode, the port is considered a "failure" for the purposes of end-to-end link integrity because the end-to-end Ethernet path is unavailable. The port "failure" also cause both ends of the path to be disabled.

13.1.4 Gigabit EtherChannel/802.3ad Link Aggregation

The end-to-end Ethernet link integrity feature of the G1000-4 can be used in combination with Gigabit EtherChannel capability on attached devices. The combination provide an Ethernet traffic restoration scheme that has a faster response time than alternate techniques such as spanning tree re-routing, yet is more bandwidth efficient because spare bandwidth does not need to be reserved.

The G1000-4 supports all forms of Link Aggregation technologies including Gigabit EtherChannel (GEC) which is a Cisco proprietary standard as well as the IEEE 802.3ad standard. The end-to- end link integrity feature of the G1000-4 allows a circuit to emulate an Ethernet link. This allows all flavors of layer 2 and layer 3 re-routing, as well as technologies such as link aggregation, to work correctly with the G1000-4. The G1000-4 supports Gigabit EtherChannel (GEC), which is a Cisco proprietary standard similar to the IEEE link aggregation standard (IEEE 802.3ad). Figure 13-3 illustrates G1000-4 GEC support.

Figure 13-3 G1000-4 Gigabit EtherChannel (GEC) support

Although the G1000-4 card does not actively run GEC, it supports the end-to-end GEC functionality of attached Ethernet devices. If two Ethernet devices running GEC connect through G1000-4 cards to an ONS 15454 network, the ONS 15454 SONET side network is transparent to the EtherChannel devices. The EtherChannel devices operate as if they are directly connected to each other. Any combination of G1000-4 parallel circuit sizes can be used to support GEC throughput.

GEC provides line-level active redundancy and protection (1:1) for attached Ethernet equipment. It can also bundle parallel G1000-4 data links together to provide more aggregated bandwidth. Spanning Tree (STP) operates as if the bundled links are one link and permits GEC to utilize these multiple parallel paths. Without GEC, STP only permits a single non-blocked path. GEC can also provide G1000-4 card-level protection or redundancy because it can support a group of ports on different cards (or different nodes) so that if one port or card has a failure, then traffic is re-routed over the other port/card.

13.2 E Series Application

The E series cards incorporate layer 2 switching, while the G series card is a straight mapper card. The ONS 15454 E series cards include the E100T-12/E100T-G and E1000-2/E1000-2-G. E series cards support VLAN, IEEE 802.1Q, spanning tree, and IEEE 802.1D. An ONS 15454 holds a maximum of ten Ethernet cards, and you can insert Ethernet cards in any multipurpose slot.

The E100T-G is the functional equivalent of the E100T-12. An ONS 15454 using XC10G cards requires the G versions of the E series Ethernet cards. The E1000-2 is the functional equivalent of the E1000-2-G. An ONS 15454 using XC10G cards requires the G versions of the E series Ethernet cards.

13.2.1 E Series Multicard and Single-Card EtherSwitch

The ONS 15454 enables multicard and single-card EtherSwitch modes for E series cards. At the Ethernet card view in CTC, click the Provisioning > Ether Card tabs to reveal the Card Mode option.

13.2.1.1 E Series Multicard EtherSwitch

Multicard EtherSwitch provisions two or more Ethernet cards to act as a single layer 2 switch. It supports one STS-6c shared packet ring, two STS-3c shared packet rings, or six STS-1 shared packet rings. The bandwidth of the single switch formed by the Ethernet cards matches the bandwidth of the provisioned Ethernet circuit up to STS-6c worth of bandwidth.

Figure 13-4 A Multicard EtherSwitch configuration


Caution Whenever you drop two STS-3c multicard EtherSwitch circuits onto an Ethernet card and delete only the first circuit, you should not provision STS-1 circuits to the card without first deleting the remaining STS-3c circuit. If you attempt to create a STS-1 circuit after deleting the first STS-3c circuit, the STS-1 circuit will not work and no alarms will indicate this condition. To avoid this condition, delete the second STS-3c prior to creating the STS-1 circuit.

13.2.1.2 E Series Single-Card EtherSwitch

Single-card EtherSwitch allows each Ethernet card to remain a single switching entity within the ONS 15454 shelf. This option allows a full STS-12c worth of bandwidth between two Ethernet circuit points. Figure 13-5 illustrates a single-card EtherSwitch configuration.

Figure 13-5 A Single-card EtherSwitch configuration

Seven scenarios exist for provisioning single-card EtherSwitch bandwidth:

1. STS 12c

2. STS 6c + STS 6c

3. STS 6c + STS 3c + STS 3c

4. STS 6c + 6 STS-1s

5. STS 3c + STS 3c +STS 3c +STS 3c

6. STS 3c +STS 3c + 6 STS-1s

7. 12 STS-1s


Note When configuring scenario 3, the STS 6c must be provisioned before either of the STS 3c circuits.


13.2.2 ONS 15454 E Series and ONS 15327 EtherSwitch Circuit Combinations

The following table shows the Ethernet circuit combinations available in ONS 15454 E series cards and ONS 15327s.

Table 13-1 ONS 15454 and ONS 15327 Ethernet Circuit Combinations

15327 Single-Card
15327 Multicard
15454 E Series Single-Card
15454 E Series Multicard

six STS-1s

three STS-1s

one STS 12c

six STS-1s

two STS 3cs

one STS 3c

two STS 6cs

two STS 3cs

one STS 6c

 

one STS 6c and two STS 3cs

one STS 6c

one STS 12c

 

one STS 6c and six STS-1s

 
   

four STS 3cs

 
   

two STS 3cs and six STS-1s

 
   

twelve STS-1s

 

13.3 E Series Circuit Configurations

Ethernet circuits can link ONS nodes through point-to-point, shared packet ring, or hub and spoke configurations. Two nodes usually connect with a point-to-point configuration. More than two nodes usually connect with a shared packet ring configuration or a hub and spoke configuration. Ethernet manual cross-connects allow you to cross connect individual Ethernet circuits to an STS channel on the ONS 15454 optical interface and also to bridge non-ONS SONET network segments.

13.3.1 E-Series Circuit Protection

Different combinations of E-Series circuit configurations and SONET network topologies offer different levels of E-Series circuit protection. Table 13-2 details the available protection.

Table 13-2 Protection for E-Series Circuit Configurations 

Configuration
UPSR
BLSR
1 + 1

Point-to-Point Multicard Etherswitch

None

SONET

SONET

Point-to-Point Single-Card Etherswitch

SONET

SONET

SONET

Shared Packet Ring Multicard Etherswitch

STP

SONET

SONET

Common Control Card Switch

STP

STP

STP



Note Before making Ethernet connections, choose a STS-1, STS-3c, STS-6c, or STS-12c circuit size.



Note When making an STS-12c Ethernet circuit, Ethernet cards must be configured as Single-card EtherSwitch. Multicard mode does not support STS-12c Ethernet circuits.


13.3.2 E Series Point-to-Point Ethernet Circuits

The ONS 15454 can set up a point-to-point (straight) Ethernet circuit as Single-card or Multicard. Multicard EtherSwitch limits bandwidth to STS-6c of bandwidth between two Ethernet circuit points, but allows adding nodes and cards and making a shared packet ring. Single-card EtherSwitch allows a full STS-12c of bandwidth between two Ethernet circuit points.

Figure 13-6 A Multicard EtherSwitch point-to-point circuit

Figure 13-7 A Single-card Etherswitch point-to-point circuit

13.3.3 E Series Shared Packet Ring Ethernet Circuits

Figure 13-8 illustrates a shared packet ring. Your network architecture may differ from the example.

Figure 13-8 A shared packet ring Ethernet circuit

13.3.4 E Series Hub and Spoke Ethernet Circuit Provisioning

The hub and spoke configuration connects point-to-point circuits (the spokes) to an aggregation point (the hub). In many cases, the hub links to a high-speed connection and the spokes are Ethernet cards. Figure 13-9 illustrates a sample hub and spoke ring. Your network architecture may differ from the example.

Figure 13-9 A Hub and Spoke Ethernet circuit

13.3.5 E Series Ethernet Manual Cross-Connects

ONS 15454s require end-to-end CTC visibility between nodes for normal provisioning of Ethernet circuits. When other vendors' equipment sits between ONS 15454s, OSI/TARP- based equipment does not allow tunneling of the ONS 15454 TCP/IP-based DCC. To circumvent this lack of continuous DCC, the Ethernet circuit must be manually cross connected to an STS channel riding through the non-ONS network. This allows an Ethernet circuit to run from ONS node to ONS node utilizing the non-ONS network.

Figure 13-10 Ethernet manual cross-connects

13.4 G1000-4 Circuit Configurations

This section explains G1000-4 point-to-point circuits and Ethernet manual cross-connects. Ethernet manual cross-connects allow you to cross connect individual Ethernet circuits to an STS channel on the ONS 15454 optical interface and also to bridge non-ONS SONET network segments.

13.4.1 G1000-4 Point-to-Point Ethernet Circuits

G1000-4 cards support point-to-point circuit configuration. Provisionable circuit sizes are STS 1, STS 3c, STS 6c, STS 9c, STS 12c, STS 24c and STS 48c. Each Ethernet port maps to a unique STS circuit on the SONET side of the G1000-4.

Figure 13-11 A G1000-4 point-to-point circuit

The G1000-4 supports any combination of up to four circuits from the list of valid circuit sizes, however the circuit sizes can add up to no more than 48 STSs. Due to hardware constraints, the card imposes additional restrictions on the combinations of circuits that can be dropped onto a G1000-4 card. These restrictions are transparently enforced by the ONS 15454, and you do not need to keep track of restricted circuit combinations.

The restriction occurs when a single STS-24c is dropped on a card. In this instance, the remaining circuits on that card can be another single STS-24c or any combination of circuits of STS-12c size or less that add up to no more than 12 STSs (i.e. a total of 36 STSs on the card).

No circuit restrictions are present, if STS-24c circuits are not being dropped on the card. The full 48 STSs bandwidth can be used (for example using either a single STS-48c or 4 STS-12c circuits).


Note Since the restrictions only apply when STS-24cs are involved but do not apply to two STS-24c circuits on a card, you can easily minimize the impact of these restrictions. Group the STS-24c circuits together on a card separate from circuits of other sizes. The grouped circuits can be dropped on other G1000-4 cards on the ONS 15454.



Note The G1000-4 uses STS cross-connects only. No VT level cross-connects are used.



Note All SONET side STS circuits must be contiguous.



Caution G1000-4 circuits connect with OC-N cards or other G1000-4 cards. G1000-4 cards do not connect with E-series Ethernet cards.


Caution The G1000-4 card requires the XC10G card to operate. The G1000-4 card is not compatible with XC or XCVT cards.

13.4.2 G1000-4 Manual Cross-Connects

ONS 15454s require end-to-end CTC visibility between nodes for normal provisioning of Ethernet circuits. When other vendors' equipment sits between ONS 15454s, OSI/TARP-based equipment does not allow tunneling of the ONS 15454 TCP/IP-based DCC. To circumvent a lack of continuous DCC, the Ethernet circuit must be manually cross connected to an STS channel riding through the non-ONS network. This allows an Ethernet circuit to run from ONS node to ONS node while utilizing the non-ONS network.


Note In this chapter, "cross-connect" and "circuit" have the following meanings: Cross-connect refers to the connections that occur within a single ONS 15454 to allow a circuit to enter and exit an ONS 15454. Circuit refers to the series of connections from a traffic source (where traffic enters the ONS 15454 network) to the drop or destination (where traffic exits an ONS 15454 network).


Figure 13-12 G1000-4 manual cross-connects

13.5 E Series VLAN Support

Users can provision up to 509 VLANs with the CTC software. Specific sets of ports define the broadcast domain for the ONS 15454. The definition of VLAN ports includes all Ethernet and packet-switched SONET port types. All VLAN IP address discovery, flooding, and forwarding is limited to these ports.

The ONS 15454 802.1Q-based VLAN mechanism provides logical isolation of subscriber LAN traffic over a common SONET transport infrastructure. Each subscriber has an Ethernet port at each site, and each subscriber is assigned to a VLAN. Although the subscriber's VLAN data flows over shared circuits, the service appears to the subscriber as a private data transport.

13.5.1 E Series Q-Tagging (IEEE 802.1Q)

IEEE 802.1Q allows the same physical port to host multiple 802.1Q VLANs. Each 802.1Q VLAN represents a different logical network.

The ONS 15454 works with Ethernet devices that support IEEE 802.1Q and those that do not support IEEE 802.1Q. If a device attached to an ONS 15454 Ethernet port does not support IEEE 802.1Q, the ONS 15454 only uses Q-tags internally. The ONS 15454 associates these Q-tags with specific ports.

With Ethernet devices that do not support IEEE 802.1Q, the ONS 15454 takes non-tagged Ethernet frames that enter the ONS network and uses a Q-tag to assign the packet to the VLAN associated with the ONS network's ingress port. The receiving ONS node removes the Q-tag when the frame leaves the ONS network (to prevent older Ethernet equipment from incorrectly identifying the 8021.Q packet as an illegal frame). The ingress and egress ports on the ONS network must be set to Untag for the process to occur. Untag is the default setting for ONS ports. Example #1 in Figure 13-13 illustrates Q-tag use only within an ONS network.

With Ethernet devices that support IEEE 802.1Q, the ONS 15454 uses the Q-tag attached by the external Ethernet devices. Packets enter the ONS network with an existing Q-tag; the ONS 15454 uses this same Q-tag to forward the packet within the ONS network and leaves the Q-tag attached when the packet leaves the ONS network. Set both entry and egress ports on the ONS network to Tagged for this process to occur. Example #2 in Figure 13-13 illustrates the handling of packets that both enter and exit the ONS network with a Q-tag.

For more information about setting ports to Tagged and Untag, refer to the Provision E Series Ethernet Ports for VLAN Membership (DLP102) in the Cisco ONS 15454 Procedures Guide.

Figure 13-13 A Q-tag moving through a VLAN

13.5.2 E Series Priority Queuing (IEEE 802.1Q)


Note IEEE 802.1Q was formerly IEEE 802.1P.


Networks without priority queuing handle all packets on a first-in-first-out basis. Priority queuing reduces the impact of network congestion by mapping Ethernet traffic to different priority levels. The ONS 15454 supports priority queuing. The ONS 15454 takes the eight priorities specified in IEEE 802.1Q and maps them to two queues ( Table 13-3). Q-tags carry priority queuing information through the network.

The ONS 15454 uses a "leaky bucket" algorithm to establish a weighted priority (not a strict priority). A weighted priority gives high-priority packets greater access to bandwidth, but does not totally preempt low-priority packets. During periods of network congestion, roughly 70% of bandwidth goes to the high-priority queue and the remaining 30% goes to the low-priority queue. A network that is too congested will drop packets.

Table 13-3 Priority Queuing

User Priority
Queue
Allocated Bandwidth

0,1,2,3

Low

30%

4,5,6,7

High

70%


Figure 13-14 The priority queuing process

13.5.3 E Series VLAN Membership

This section explains how to provision Ethernet ports for VLAN membership. For initial port provisioning (prior to provisioning VLAN membership) refer to the Provision E Series Ethernet Ports (DLP101) in the Cisco ONS 15454 Procedures Guide.


Caution ONS 15454s propagate VLANs whenever a node appears on the same network view of another node regardless of whether the nodes connect through DCC. For example, if two ONS 15454s without DCC connectivity belong to the same Login Node Group, then whenever CTC gets launched from within this login node group, VLANs propagate from one to another. This happens even though the ONS 15454s do not belong to the same SONET ring.

13.5.4 VLAN Counter

The ONS 15454 displays the number of VLANs used by circuits and the total number of VLANs available for use. To display the number of available VLANs and the number of VLANs used by circuits, click the Circuits tab and click an existing Ethernet circuit to highlight it. Click Edit. Click the VLANs tab.

Figure 13-15 Edit Circuit dialog featuring available VLANs

13.6 E Series Spanning Tree (IEEE 802.1D)

The Cisco ONS 15454 operates spanning tree protocol (STP) according to IEEE 802.1D when an Ethernet card is installed. STP operates over all packet-switched ports including Ethernet and OC-N ports. On Ethernet ports, STP is enabled by default but may be disabled with a check box under the Provisioning > Ether Port tabs at the card-level view. A user can also disable or enable spanning tree on a circuit-by-circuit basis on unstitched Ethernet cards in a point-to-point configuration. However, turning off spanning tree protection on a circuit-by-circuit basis means that the ONS 15454 system is not protecting the Ethernet traffic on this circuit, and the Ethernet traffic must be protected by another mechanism in the Ethernet network. On OC-N interface ports, STP activates by default and cannot be disabled.

The Ethernet card can enable STP on the Ethernet ports to allow redundant paths to the attached Ethernet equipment. STP spans cards so that both equipment and facilities are protected against failure.

STP detects and eliminates network loops. When STP detects multiple paths between any two network hosts, STP blocks ports until only one path exists between any two network hosts ( Figure 13-16). The single path eliminates possible bridge loops. This is crucial for shared packet rings, which naturally include a loop.

Figure 13-16 An STP blocked path

To remove loops, STP defines a tree that spans all the switches in an extended network. STP forces certain redundant data paths into a standby (blocked) state. If one network segment in the STP becomes unreachable, the spanning-tree algorithm reconfigures the spanning-tree topology and reactivates the blocked path to reestablish the link. STP operation is transparent to end stations, which do not discriminate between connections to a single LAN segment or to a switched LAN with multiple segments. The ONS 15454 supports one STP instance per circuit and a maximum of eight STP instances per ONS 15454.


Caution Multiple circuits with spanning tree protection enabled will incur blocking, if the circuits traverse a common card and uses the same VLAN.

13.6.1 E Series Multi-Instance Spanning Tree and VLANs

The ONS 15454 can operate multiple instances of STP to support VLANs in a looped topology. You can dedicate separate circuits across the SONET ring for different VLAN groups (i.e., one for private TLS services and one for Internet access). Each circuit runs its own STP to maintain VLAN connectivity in a multi-ring environment.

13.6.2 Spanning Tree on a Circuit-by-Circuit Basis

A user can also disable or enable spanning tree on a circuit-by-circuit basis on unstitched Ethernet cards in a point-to-point configuration. This feature allows customers to mix spanning tree protected circuits with unprotected circuits on the same card. It also allows two single-card E-series Ethernet cards on the same node to form an intranode circuit.

13.6.3 E Series Spanning Tree Parameters

Default spanning tree parameters are appropriate for most situations. Contact the Cisco Technical Assistance Center (TAC) at 1-877-323-7368 before you change the default STP parameters.

At the node view, click the Maintenance > Etherbridge > Spanning Trees tabs to view spanning tree parameters.

Table 13-4 Spanning Tree Parameters 

BridgeID

ONS 15454 unique identifier that transmits the configuration bridge protocol data unit (BPDU); the bridge ID is a combination of the bridge priority and the ONS 15454 MAC address

TopoAge

Amount of time in seconds since the last topology change

TopoChanges

Number of times the spanning tree topology has been changed since the node booted up

DesignatedRoot

Identifies the spanning tree's designated root for a particular spanning tree instance

RootCost

Identifies the total path cost to the designated root

RootPort

Port used to reach the root

MaxAge

Maximum time that received-protocol information is retained before it is discarded

HelloTime

Time interval, in seconds, between the transmission of configuration BPDUs by a bridge that is the spanning tree root or is attempting to become the spanning tree root

HoldTime

Minimum time period, in seconds, that elapses during the transmission of configuration information on a given port

ForwardDelay

Time spent by a port in the listening state and the learning state


13.6.4 E Series Spanning Tree Configuration

To view the spanning tree configuration, at the node view click the Provisioning > Etherbridge > Spanning Trees tabs.

Table 13-5 Spanning Tree Configuration

Column
Default Value
Value Range

Priority

32768

0 - 65535

Bridge max age

20 seconds

6 - 40 seconds

Bridge Hello Time

2 seconds

1 - 10 seconds

Bridge Forward Delay

15 seconds

4 - 30 seconds


13.6.5 E Series Spanning Tree Map

The Circuit screen shows forwarding spans and blocked spans on the spanning tree map.

Figure 13-17 The spanning tree map on the circuit screen


Note Green represents forwarding spans and purple represents blocked (protect) spans. If you have a packet ring configuration, at least one span should be purple.


13.7 G1000-4 Performance and Maintenance Screens

CTC provides Ethernet performance information, including line-level parameters, the amount of port bandwidth used, and historical Ethernet statistics. CTC also includes spanning tree information, MAC address information, and the amount of circuit bandwidth used.

13.7.1 G1000-4 Ethernet Performance Screen

CTC provides Ethernet performance information that include line-level parameters, the amount of port bandwidth used, and historical Ethernet statistics.

13.7.1.1 Statistics Window

The Ethernet statistics screen lists Ethernet parameters at the line level. Display the CTC card view for the Ethernet card and click the Performance > Statistics tabs to display the screen.

Figure 13-18 G1000-4 Statistics window

Table 13-6 G1000-4 Statistics Values

Baseline

Clicking Baseline resets the software counters (in that particular CTC client only) temporarily to zero without affecting the actual statistics on the card. From that point on, only the change (delta) in counters are displayed by this CTC. These new base lined counters display only as long as the user displays the Performance pane. If the user navigates to another pane and comes back to the Performance pane, the true actual statistics retained by the card display.

Refresh

Manually refreshes the statistics

Auto-Refresh

Sets a time interval for the automatic refresh of statistics

Clear

Resets the actual counters on the card to zero; this change is recognized by all management clients.



Note The CTC automatically refreshes the counter values once right after a Baseline operation, so if traffic is flowing during a baseline operation, some traffic counts may immediately be observed instead of zero counts.



Note The Clear button will not cause the G1000-4 card to reset. Provisioning, enabling, or disabling a G1000-4 port will not reset the statistics.



Note You can apply both the Baseline and the Clear functions to a single port or all ports on the card. To apply Baseline or Clear to a single port, click the port column to highlight the port and click the Baseline or Clear button.


Table 13-7 Ethernet Parameters 

Parameter
Meaning

Link Status

Indicates whether the Ethernet link is receiving a valid Ethernet signal (carrier) from the attached Ethernet device; up means present, and down means not present

Rx Packets

Number of packets received since the last counter reset

Rx Bytes

Number of bytes received since the last counter reset

Tx Packets

Number of packets transmitted since the last counter reset

Tx Bytes

Number of bytes transmitted since the last counter reset

Rx Total Errors

Total number of receive errors

Rx FCS

Number of packets with a Frame Check Sequence (FCS) error. FCS errors indicate Frame corruption during transmission

Rx Alignment

Number of packets with alignment errors; alignment errors are received incomplete frames

Rx Runts

The total number of frames received that are less than 64 bytes in length and have a CRC error

Rx Jabbers

The total number of frames received that exceed the maximum 1548 bytes and contain CRC errors

Rx Giants

Number of packets received that are greater than 1548 bytes in length

Rx Pause Frames (G series only)

Number of received Ethernet 802.3x pause frames

Tx Pause Frames (G series only)

Number of transmitted 802.3x pause frames

Rx Pkts Dropped Internal Congestion (G series only)

Number of received packets dropped due to overflow in G1000-4 frame buffer

Tx Pkts Dropped Internal Congestion (G series only)

Number of transmit queue drops due to drops in the G1000-4 frame buffer

HDLC errors (G series only)

HDLC errors received from SONET/SDH (see note)



Note The HDLC errors counter should not be used to count the number of frames dropped due to HDLC errors as each frame can get fragmented into several smaller frames during HDLC error conditions and spurious HDLC frames can also generate. If these counters are incrementing at a time when there should be no SONET path problems that may indicate a problem with the quality of the SONET path. For example, a SONET protection switch causes a set of HLDC errors to generate. The actual values of these counters are less relevant than the fact they are changing.


13.7.1.2 Utilization Window

The Utilization subtab shows the percentage of current and past line bandwidth used by the Ethernet ports. Display the CTC card view and click the Performance > Utilization tabs to display the screen. From the Interval menu, choose a time segment interval. Valid intervals are 1 minute, 15 minutes, 1 hour, and 1 day. Press Refresh to update the data.


Note The G Series card does not display statistics on the Trunk Utilization screen, since the G Series card is not a layer two device or switch. The E Series cards is a layer two device or switch and supports the Trunk Utilization screen. The Trunk Utilization screen is similar to the Line Utilization screen, but Trunk Utilization shows the percentage of circuit bandwidth used rather than the percentage of line bandwidth.


13.7.1.3 Utilization Formula

Line utilization is calculated with the following formula:

((inOctets + outOctets) + (inPkts + outPkts) * 20)) * 8 / 100% interval * maxBaseRate * 2.

The interval is defined in seconds. maxBaseRate is defined by raw bits/second in one direction for the Ethernet port (i.e. 1 Gbps). maxBaseRate is multiplied by 2 in the denominator to determine the raw bit rate in both directions.

13.7.1.4 History Window

The Ethernet History subtab lists past Ethernet statistics. At the CTC card view, click the Performance tab and History subtab to view the screen. Choose the appropriate port from the Line menu and the appropriate interval from the Interval menu. Press Refresh to update the data.

13.7.2 G1000-4 Ethernet Maintenance Screen

When a G1000-4 card is installed in the ONS 15454, the Maintenance tab under CTC card view reveals a Maintenance screen with two tabs Loopback and Bandwidth. The Loopback screen allows you put an individual G1000-4 port into a Terminal (inward) loopback. The Bandwidth screen displays the amount of current STS bandwidth the card is using.

Figure 13-19 The G1000-4 Maintenance tab, including loopback and bandwidth information

Table 13-8 G1000-4 Maintenance Screen Values

Loopback

Displays the Loopback status of the G1000-4 port

Bandwidth

Displays the amount of STS bandwidth provisioned for the G1000-4 card.

#

Specifies the specific port number on the G1000-4 card

Loopback Type

Allows you to configure a port for a Terminal (Inward) loopback or clear the current loopback (none)

Apply

Enables the Loopback configuration on the port

State

Displays the state of the port in the # field (In Service, Out of Service, Out of Service-Maintenance, Out of Service-Auto In Service).



Caution Use Loopback only for the initial test and turn-up of the card and SONET network tests. Do not put the card in Loopback when the G1000-4 ports are in service and attached to a data network. Loopbacks can corrupt the forwarding tables used in data networking.


Note For more information about using loopbacks with the ONS 15454, refer to the Cisco ONS 15454 Troubleshooting Guide.


13.7.3 E-Series Ethernet Performance Screen

CTC provides Ethernet performance information that includes line-level parameters, the amount of port bandwidth used, and historical Ethernet statistics.

13.7.3.1 Statistics Window

The Ethernet statistics screen lists Ethernet parameters at the line level. Table 13-9 defines the parameters. Display the CTC card view for the Ethernet card and click the Performance > Statistics tabs to display the screen.

The Baseline button resets the statistics values on the Statistics screen to zero. The Refresh button manually refreshes statistics. Auto-Refresh sets a time interval for automatic refresh of statistics to occur.

The G1000-4 Statistics screen also has a Clear button. The Clear button sets the values on the card to zero. Using the Clear button will not cause the G1000-4 to reset.

Table 13-9 Ethernet Parameters 

Parameter
Meaning

Link Status

Indicates whether link integrity is present; up means present, and down means not present

Rx Packets

Number of packets received since the last counter reset

Rx Bytes

Number of bytes received since the last counter reset

Tx Packets

Number of packets transmitted since the last counter reset

Tx Bytes

Number of bytes transmitted since the last counter reset

Rx Total Errors

Total number of receive errors

Rx FCS

Number of packets with a Frame Check Sequence (FCS) error. FCS errors indicate Frame corruption during transmission

Rx Alignment

Number of packets with alignment errors; alignment errors are received incomplete frames

Rx Runts

Number of packets received that are less than 64 bytes in length

Rx Jabbers (G series only)

Total number of Octets of data (including bad packets) received on the network

Rx Giants

Number of packets received that are greater than 1518 bytes in length for untagged interfaces and 1522 bytes for tagged interfaces

Tx Collisions (E series only)

Number of transmit packets that are collisions; the port and the attached device transmitting at the same time caused collisions

Tx Late Collisions (E series only)

This counter contains the number of frames that were not transmitted since they encountered a collision outside of the normal collision window. Normally, late collision events should occur only rarely, if at all.

Tx Excessive (E series only)

Number of consecutive collisions

Tx Deferred (E series only)

Number of packets deferred

Rx Pause Frames (G series only)

Number of received Ethernet 802.3x pause frames.

Tx Pause Frames (G series only)

Number of transmitted 802.3x pause frames.

Rx Pkts Dropped Internal Congestion (G series only)

Number of received packets dropped due to overflow in G1000-4 frame buffer.

Tx Pkts Dropped Internal Congestion (G series only)

Number of transmit que drops due to drops in G1000-4 frame buffer

HDLC Errors (G series only)

HDLC Errors received by SONET (See note)



Note The HDLC errors counter should not be used to count the number of frames dropped due to HDLC errors as each frame can get fragmented into several smaller frames during HDLC error conditions and spurious HDLC frames can also generate. If these counters are incrementing at a time when there should be no SONET path problems that may indicate a problem with the quality of the SONET path. For example, a SONET protection switch causes a set of HLDC errors to generate. The actual values of these counters is less relevant than the fact they are changing.


13.7.3.2 Line Utilization Window

The Line Utilization window shows the percentage of line, or port, bandwidth used and the percentage used in the past. Display the CTC card view and click the Performance and Utilization tabs to display the screen. From the Interval menu, choose a time segment interval. Valid intervals are 1 minute, 15 minutes, 1 hour, and 1 day. Press Refresh to update the data.

13.7.3.3 E Series Utilization Formula

Line utilization is calculated with the following formula:

((inOctets + outOctets) + (inPkts + outPkts) * 20)) * 8 / 100 % interval * maxBaseRate * 2.

The interval is defined in seconds. maxBaseRate is defined by raw bits/second in one direction for the Ethernet port (i.e. 1 Gbps). maxBaseRate is multiplied by 2 in the denominator to determine the raw bit rate in both directions.

Table 13-10 maxRate for STS circuits

STS-1

51840000

STS-3c

155000000

STS-6c

311000000

STS-12c

622000000



Note Line utilization numbers express the average of ingress and egress traffic as a percentage of capacity.


13.7.3.4 History Window

The Ethernet History screen lists past Ethernet statistics. At the CTC card view, click the Performance tab and History subtab to view the screen. Choose the appropriate port from the Line menu and the appropriate interval from the Interval menu. Press Refresh to update the data. Table 13-9 defines the listed parameters.

13.7.4 E-Series Ethernet Maintenance Screen

In CTC node view, click the Maintenance > Etherbridge > Mac Table tab to display MAC address and bandwidth information for an ONS 15454 containing one or more E-series card.

13.7.4.1 MAC Table Window

A MAC address is a hardware address that physically identifies a network device. The ONS 15454 MAC table, also known as the MAC forwarding table, will allow you to see all the MAC addresses attached to the enabled ports of an E series Ethernet card or an E series Ethernet Group. This includes the MAC address of the network device attached directly to the port and any MAC addresses on the network linked to the port. The MAC addresses table lists the MAC addresses stored by the ONS 15454 and the VLAN, Slot/Port/STS, and circuit that links the ONS 15454 to each MAC address ( Figure 13-20). To retrieve the MAC address table through CTC, click the Maintenance > EtherBridge > MAC Table tabs, choose the appropriate Ethernet card or Ethergroup from the Layer 2 Domain pull-down menu, and click Refresh. Click Clear to clear the highlighted rows and click Clear All to clear all displayed rows.

Figure 13-20 MAC addresses recorded in the MAC table

13.7.4.2 Trunk Utilization Window

The Trunk Utilization screen is similar to the Line Utilization screen, but Trunk Utilization shows the percentage of circuit bandwidth used rather than the percentage of line bandwidth used. Click the Maintenance > Ether Bridge > Trunk Utilization tabs to view the screen. Choose a time segment interval from the Interval menu.


Note The percentage shown is the average of ingress and egress traffic.


13.8 Remote Monitoring Specification Alarm Thresholds

The ONS 15454 features Remote Monitoring (RMON) that allows network operators to monitor the health of the network with a Network Management System (NMS).

One of the ONS 15454's RMON MIBs is the Alarm group. The alarm group consists of the alarmTable. An NMS uses the alarmTable to find the alarm-causing thresholds for network performance. The thresholds apply to the current 15-minute interval and the current 24-hour interval. RMON monitors several variables, such as Ethernet collisions, and triggers an event when the variable crosses a threshold during that time interval. For example, if a threshold is set at 1000 collisions and 1001 collisions occur during the 15-minute interval, an event triggers. CTC allows you to provision these thresholds for Ethernet statistics.


Note The following tables define the variables you can provision in CTC. For example, to set the collision threshold, choose etherStatsCollisions from the Variable menu.


Table 13-11 Ethernet Threshold Variables (MIBs) 

Variable
Definition

iflnOctets

Total number of octets received on the interface, including framing octets

iflnUcastPkts

Total number of unicast packets delivered to an appropriate protocol

ifInMulticastPkts

Number of multicast frames received error free

ifInBroadcastPkts

The number of packets, delivered by this sub-layer to a higher (sub-)layer, which were addressed to a broadcast address at this sub-layer

ifInDiscards

The number of inbound packets which were chosen to be discarded even though no errors had been detected to prevent their being deliverable to a higher-layer protocol

iflnErrors

Number of inbound packets discarded because they contain errors

ifOutOctets

Total number of transmitted octets, including framing packets

ifOutUcastPkts

Total number of unicast packets requested to transmit to a single address

ifOutMulticastPkts

Number of multicast frames transmitted error free

ifOutBroadcastPkts

The total number of packets that higher-level protocols requested be transmitted, and which were addressed to a broadcast address at this sub-layer, including those that were discarded or not sent

ifOutDiscards

The number of outbound packets which were chosen to be discarded even though no errors had been detected to prevent their being transmitted

dot3statsAlignmentErrors

Number of frames with an alignment error, i.e., the length is not an integral number of octets and the frame cannot pass the Frame Check Sequence (FCS) test

dot3StatsFCSErrors

Number of frames with framecheck errors, i.e., there is an integral number of octets, but an incorrect Frame Check Sequence (FCS)

dot3StatsSingleCollisionFrames

Number of successfully transmitted frames that had exactly one collision

dot3StatsMutlipleCollisionFrame

Number of successfully transmitted frames that had multiple collisions

dot3StatsDeferredTransmissions

Number of times the first transmission was delayed because the medium was busy

dot3StatsLateCollision

Number of times that a collision was detected later than 64 octets into the transmission (also added into collision count)

dot3StatsExcessiveCollision

Number of frames where transmissions failed because of excessive collisions

dot3StatsCarrierSenseErrors

The number of transmission errors on a particular interface that are not otherwise counted.

dot3StatsSQETestErrors

A count of times that the SQE TEST ERROR message is generated by the PLS sublayer for a particular interface

etherStatsJabbers

Total number of Octets of data (including bad packets) received on the network

etherStatsUndersizePkts

Number of packets received with a length less than 64 octets

etherStatsFragments

Total number of packets that are not an integral number of octets or have a bad FCS, and that are less than 64 octets long

etherStatsPkts64Octets

Total number of packets received (including error packets) that were 64 octets in length

etherStatsPkts65to127Octets

Total number of packets received (including error packets) that were 65 - 172 octets in length

etherStatsPkts128to255Octets

Total number of packets received (including error packets) that were 128 - 255 octets in length

etherStatsPkts256to511Octets

Total number of packets received (including error packets) that were 256 - 511 octets in length

etherStatsPkts512to1023Octets

Total number of packets received (including error packets) that were 512 - 1023 octets in length

etherStatsPkts1024to1518Octets

Total number of packets received (including error packets) that were 1024 - 1518 octets in length

etherStatsJabbers

Total number of packets longer than 1518 octets that were not an integral number of octets or had a bad FCS

etherStatsCollisions

Best estimate of the total number of collisions on this segment

etherStatsCollisionFrames

Best estimate of the total number of frame collisions on this segment

etherStatsCRCAlignErrors

Total number of packets with a length between 64 and 1518 octets, inclusive, that had a bad FCS or were not an integral number of octets in length

receivePauseFrames (G series only)

The number of received 802.x pause frames

transmitPauseFrames(G series only)

The number of transmitted 802.x pause frames

receivePktsDroppedInternalCongestion(G series only)

The number of received frames dropped due to frame buffer overflow as well as other reasons

transmitPktsDroppedInternalCongestion(G series only)

The number of frames dropped in the transmit direction due to frame buffer overflow as well as other reasons

txTotalPkts

Total number of transmit packets

rxTotalPkts

Total number of receive packets