user manual

REVIEW DRAFT—CISCO CONFIDENTIAL
14-2
Cisco ONS 15454 SDH Reference Manual, R5.0
April 2008
Chapter 14 Ethernet Operation
14.1.1 G1K-4 and G1000-4 Comparison
The G-Series cards allow an Ethernet private line service to be provisioned and managed very much like
a traditional SDH or SONET line. G-Series 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.
The card maps a single Ethernet port to a single STM circuit. You can independently map the four ports
on the G-Series card to any combination of VC4, VC4-2c, VC4-3c, VC4-4c, VC4-8c, and VC4-16C
circuit sizes, provided the sum of the circuit sizes that terminate on a card do not exceed VC4-16C.
To support a Gigabit Ethernet port at full line rate, an STM circuit with a capacity greater or equal to
1 Gbps (bidirectional 2 Gbps) is needed. A VC4-8c is the minimum circuit size that can support a
Gigabit Ethernet port at full line rate. The G-Series card supports a maximum of two ports at full line
rate.
The G-Series transmits and monitors the SDH J1 Path Trace byte in the same manner as
ONS 15454 SDH STM-N cards. For more information, see the “10.9 Path Trace” section on page 10-15.
Note G-Series encapsulation is standard high-level data link control (HDLC) framing over SONET/SDH as
described in RFC 1622 and RFC 2615 with the point-to-point protocol (PPP) field set to the value
specified in RFC 1841.
14.1.1 G1K-4 and G1000-4 Comparison
The G1K-4 and the G1000-4 cards constitute the ONS 15454 SDH G-Series and are hardware
equivalents. Software releases prior to R4.0 identify both the G1000-4 and the G1K-4 as G1000-4 cards
when they are physically installed. Software R4.0 and later identify G1K-4 cards correctly (that is, as
GIK-4 cards) when they are physically installed.
14.1.2 G-Series Example
Figure 14-1 shows an example of a G-Series application. In this example, data traffic from the Gigabit
Ethernet port of a high-end router travels across the ONS 15454 SDH point-to-point circuit to the Gigabit
Ethernet port of another high-end router.
Figure 14-1 Data Traffic on a G-Series Point-to-Point Circuit
The G-Series card carries any Layer 3 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 a standard Gigabit
Interface Converter (GBIC) on a G-Series card. The G-Series card transparently maps Ethernet frames
into the SDH payload by multiplexing the payload onto an SDH STM-N card. When the SDH payload
reaches the destination node, the process is reversed and the data is transmitted from the standard Cisco
GBIC in the destination G-Series card onto the Gigabit Ethernet fiber.
71323
VC4-N
SDH
802.3x pause frames sent
to throttle down source
Gig-E
ONS 15454
SDH
ONS 15454
SDH
802.3x pause frames sent
to throttle down source
Gig-E