Chapter 12, 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."

12.1 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)

•

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 1Gbps (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 Provision Path Trace on Circuit Source and Destination Ports Procedure (DLP130) in the Cisco ONS 15454 Procedure Guide. For more information on Ethernet cards, refer to the Ethernet Cards Reference Chapter.

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.

12.1.1 G1000-4 Example

Figure 12-1 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.

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 60-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.

12.1.2 802.3x 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 12-1 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:

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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.

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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.

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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.

12.1.3 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.

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 uni-directional traffic flow, if flow control is not enabled on the test set or other Ethernet device.

As shown in Figure 12-2, 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.

12.1.4 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 Ether Channel 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 12-3 illustrates G1000-4 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.

12.2 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. For more information on Ethernet cards, see the Ethernet Cards Reference Chapter.

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.

12.2.1 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 > Card tabs to reveal the Card Mode option.

12.2.1.1 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.

12.2.1.2 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 12-5 illustrates a single-card EtherSwitch configuration.

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

12.2.2 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.

12.3 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.

12.3.1 E-Series Circuit Protection

Table 12-1 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

Different combinations of E-Series circuit configurations and SONET network topologies offer different levels of E-Series circuit protection. Table 12-2 details the available protection.

Table 12-2 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.

12.3.2 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.

12.3.3 E Series Shared Packet Ring Ethernet Circuits

Figure 12-8 illustrates a shared packet ring. Your network architecture may differ from the example.

12.3.4 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 12-9 illustrates a sample hub and spoke ring. Your network architecture may differ from the example.

12.3.5 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.

12.4 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.

12.4.1 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.

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 initial release of this card (software release 3.2) 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.

12.4.2 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).

12.5 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.

12.5.1 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 12-13 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 12-13 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.

12.5.2 E Series Priority Queuing (IEEE 802.1Q)

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 12-3). 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 12-3 Priority Queuing
User Priority	Queue	Allocated Bandwidth
0,1,2,3	Low	30%
4,5,6,7	High	70%

12.5.3 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.

12.5.4 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.

12.6 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 > 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 12-16). The single path eliminates possible bridge loops. This is crucial for shared packet rings, which naturally include a loop.

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.

12.6.1 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.

12.6.2 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.

12.6.3 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 12-4 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

12.6.4 E Series Spanning Tree Configuration

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

Table 12-5 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

12.6.5 E Series Spanning Tree Map

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

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.

12.7 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.

12.7.1 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.

12.7.1.1 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.

Table 12-6 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 12-7 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.

12.7.1.2 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 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.

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.

12.7.1.3 Utilization 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.

12.7.1.4 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.

12.7.2 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 12-19 The G1000-4 Maintenance tab, including loopback and bandwidth information

Table 12-8 G1000-4 Maintenance Screen Values
Loopback	Displays the Loopback status of the G1000-4 port
#	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
Bandwidth	Displays the amount of STS bandwidth provisioned for the G1000-4 card.

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

12.7.3 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.

12.7.3.1 Statistics Window

The Ethernet statistics screen lists Ethernet parameters at the line level. Table 12-9 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 12-9 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 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 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

12.7.3.2 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.

12.7.3.3 E Series Utilization Formula

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

Table 12-10 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.

12.7.3.4 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 12-9 defines the listed parameters.

12.7.4 E-Series Ethernet Maintenance Screen

Display an E-series Ethernet card in CTC card view and choose the Maintenance tab to display MAC address and bandwidth information.

12.7.4.1 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 12-20). 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 Retrieve. Click Clear to clear the highlighted rows and click Clear All to clear all displayed rows.

12.7.4.2 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.

12.8 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 12-11 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

Table Of Contents

Ethernet Operation