Cisco Systems CE-100T-8 User Manual
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CHAPTER
16
CE-100T-8 Ethernet Operation
This chapter covers the operation of the CE-100T-8 (Carrier Ethernet) card supported on the ONS 15310
(15310-CE-100T-8). A CE-100T-8 card is also supported on the ONS 15454 (15454-CE-100T-8).
Provisioning is done through Cisco Transport Controller (CTC) or Transaction Language One (TL1).
Cisco IOS is not supported on the CE-100T-8 card.
For Ethernet card specifications, refer to the Cisco ONS 15310-CL Reference Manual. For step-by-step
Ethernet card circuit configuration procedures and hard-reset and soft-reset procedures, refer to the
Cisco ONS 15310-CL Procedure Guide. Refer to the Cisco ONS SONET TL1 Command Guide for TL1
provisioning commands. For specif ic details on ONS 15310-CL Ethernet card interoperability with other
ONS platforms, refer to the “P OS on ONS Ethernet C ards” chapter of the Ethernet Card Software
Feature and Configuration Guide for the ONS 15454 SDH, ONS 15454, and ONS 15327.
Chapter topics include:
• CE-100T-8 Overview, page 16-1
• CE-100T-8 Ethernet Features, page 16-2
• CE-100T-8 SONET Circuits and Features, page 16-6
CE-100T-8 Overview
The CE-100T-8 is a Layer 1 mapper card with eight 10/100 Ethernet ports. It maps each port to a unique
SONET circuit in a point-to-point configuration. Figure 16-1 illustrates a sample CE-100T-8
application. In this example, data traffic from the Fast Ethernet port of a switch travels across the
point-to-point circuit to the Fast Ethernet port of another switch.
Figure 16-1 CE-100T-8 Point-to-Point Circuit
Ethernet Ethernet
The CE-100T-8 cards allow you to provision and manage an Ethernet private line service like a
traditional SONET line. CE-100T-8 card applications include providing Ethernet private line services
and high-availability transport.
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Point-to-Point Circuit
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CE-100T-8 Ethernet Features
The CE-100T - 8 card supports ITU-T G.707 and Telcordia GR-253 based standards for SONET. It offers
a carrier-class level of features and reliability. This includes errorless (0-msec impact on traffic)
reprovisioning. When circuit or port provisioning takes place, this operation does not affect the
performance of other ports and circuit configurations that are already established on the card.
Software upgrades are errorless. However when the CE-100T-8 firmware is upgraded, the upgrade has
an effect on traffic similar to the effect of a hard reset on the CE-100T-8. A software upgrade or a
firmware upgrade does not affect the existing provisioning of the ports and circuits on the CE-100T-8
card.
Span upgrades are hitless. Protection and maintenance switches are also hitless.
The CE-100T-8 offers full TL1-based provisioning capability. Refer to the Cisco ONS SONET TL1
Command Guide for CE-100T-8 TL1 provisioning commands.
CE-100T-8 Ethernet Features
The CE-100T-8 card has eight front-end Ethernet ports which use standard RJ-45 connectors for
10BASE-T Ethernet/100BASE-TX Ethernet media. Ethernet Ports 1 through 8 each map to a POS port
with a corresponding number. The console port on the CE-100T-8 card is not functional.
Chapter 16 CE-100T-8 Ethernet Operation
The CE-100T-8 cards forward valid Ethernet frames unmodified over the SO NET netw ork . Informati on
in the headers is not affected by the encapsulation and transport. For example, included IEEE 802.1Q
information will travel through the process unaffected.
The ONS 15454 CE-100T-8 and the ONS 15310 CE-100T-8 support max imum Ethe rnet frame sizes of
1600 bytes including the CRC. The MTU size is not configureable and is set at a 1500 byte maximum
(standard Ethernet MTU). Baby giant frames in which the standard Ethernet frame is augmented by
802.1 Q tags or MPLS tags are also supported. Full Jumbo frames (9000 byte maximum) are not
supported.
The CE-100T-8 cards discard certain types of erroneous Ethernet frames rather than transport them over
SONET. Erroneous Ethernet frames include corrupted frames with cyclic redundancy check (CRC)
errors and undersized frames that do not conform to the minimum 64-byte length Ethernet standard.
Note Many Ethernet attributes are also available through the network element default feature. For more
information on NE defaults, refer to the "N etw ork Element Def aul ts" appendix in t he Cisco ONS 15454
Reference Manual.
Autonegotiation, Flow Control, and Frame Buffering
On the CE-100T-8, Ethernet link autonegotiation is on by default. The user can also set the link speed,
duplex, and flow control manually under the card-level Provisioning tab of CTC.
The CE-100T -8 supports IEEE 802.3x flow control and frame buf fering to reduce data traff ic congestion.
Flow control is on by default.
To prevent over-subscription, buffer memory is available for each port. When the buffer memory on the
Ethernet port nears capacity, the CE-100T-8 uses IEEE 802.3x flow control t o transmit a pause frame to
the attached Ethernet device. Flow control and autonegotiation frames are local to the Fast Ethernet
interfaces and the attached Ethernet devices. These frames do not continue through the POS ports.
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Pause Frames
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The CE-100T-8 card has symmetric flow control and proposes symmetric flow control when
autonegotiating flow control with attached Ethernet devices. Symmetric flow control allows the
CE-100T-8 cards to respond to pause frames sent from external devices and to send pause frames to
external devices.
The pause frame instructs the source to stop sending packets for a specific period of time. The sending
station waits the requested amount of time before sending more data. Figure 16-2 illustrates pause
frames being sent and received by CE-100T-8 cards and attached switches.
Figure 16-2 Flow Control
This flow-control mechanism matches the sending and receiving device throughput to that of the
bandwidth of the STS circuit. For example, a router might transmit to the Ethernet port on the CE-100T-8
card. This particular data rate might occasionally exceed 51.84 Mbps, but the SONET circuit assigned
to the CE-100T-8 port might be only STS-1 (51.84 Mbps). In this example, the CE-100T-8 sends out a
pause frame and requests that the router delay its transmission for a certain period of time. With flow
control and a substantial per-port buffering capability, a priv ate line service provisioned at less than full
line rate capacity (STS-1) is efficient because frame loss can be controlled to a large extent.
Ethernet
ONS 15310-CL ONS 15310-CL
STS-N
SONET
CE-100T-8 Ethernet Features
Ethernet
Ethernet Link Integrity Support
The CE-100T-8 supports end-to-end Ethernet link integrity (Figure 16-3). 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.
End-to-end Ethernet link integr ity means that if any p art of the end-to-end path fails, the entire path f ails.
It disables the Ethernet port on the CE-100T-8 card if the remote Ethernet port is unable to transmit over
the SONET network or if the remote Ethernet port is disabled.
Failure of the entire path is ensur ed b y t urning off the transmit pair at each end of the path. The attached
Ethernet devices recognize the disabled transmit pair a s a loss of carrier and consequently an inactive
link or link fail.
Figure 16-3 End-to-End Ethernet Link Integrity Support
thernet port
ONS 310 ONS 310
Rx
Tx
Ethernet por
STS-N
Rx
Tx
SONET
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