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Cisco 7600 Series Router SIP, SSC, and SPA Hardware Installation Guide
OL-5052-14
Chapter 3 Overview: Cisco 7600 Series Router Shared Port Adapters
1-Port Channelized STM-4/OC-12 SPA Overview
1-Port Channelized STM-4/OC-12 SPA Interface Specifications
The framer processes incoming and outgoing SONET or SDH frames. The framer operates at
OC-12/STM-4 line rates (622.08 Mbps).
Packet data is transported with a user-configured encapsulation (such as Point-to-Point Protocol [PPP])
and is mapped into the STS-12/STM-4 frame.
The 1-Port Channelized STM-4/OC-12 SPA interface is compliant with RFC 1619,
PPP over
SONET/SDH
, and RFC 1662,
PPP in HDLC-like Framing
. The 1-Port Channelized STM-4/OC-12 SPA
also provides support for SNMP v1 agent (RFC 1155–1157), and Management Information Base (MIB)
II (RFC 1213).
Note
For Cisco IOS XR Software Release 3.8.0, the 1-Port Channelized STM-4/OC-12 SPA supports Frame
Relay Fragmentation (FRF.12) to achieve fragmentation of data packets and interleaving of voice
packets. FRF.12 provides a method to fragment low-priority packets and interleave high-priority packets
in between the low-priority fragments to provide less delay or jitter for high-priority traffic like voice
and video.
Note
For Cisco IOS XR Software Release 3.8.0, the 1-Port Channelized STM-4/OC-12 SPA supports
Multilink Fame Relay (MFR) feature. MFR provides a mechanism for aggregating multiple serial links
into a bundle to provide greater bandwidth, load balancing between links, and improved service
availability by protecting against single point link failures.
1-Port Channelized STM-4/OC-12 SPA Cables and Connectors
The 1-Port Channelized STM-4/OC-12 SPA uses a small form-factor pluggable (SFP) optical transceiver
module installed in each port for SONET and SDH single-mode and multimode optical fiber connection
(see
Figure 3-9
).
Figure 3-9
SFP Optics Module
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