Difference Between POS and 10GBASE-W
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POS and 10GBASE-W cannot interoperate on the same link because the protocol architecture is
completely different. POS is based on a serial protocol, such as PPP, whose frames are logically and
physically different from the Ethernet MAC frames.
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From a service provider point of view, POS is an L3 point-to-point service, while WAN-PHY is an L2
Ethernet hand-off. It is appropriate to compare WAN-PHY with an Ethernet over SONET (EoS)
encapsulation technology, such as ITU-T X.86 or GFP (ITU-T G.7041), where the Ethernet frame is
encapsulated in an HDLC-like or GFP frame respectively.
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POS is optically and electrically compatible with SONET and SDH protocols, but WAN-PHY is not.
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POS supports linear Automatic Protection Switching (APS) to restore link failures in 50 ms, while
WAN-PHY does not support APS.
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The synchronous nature of POS requires clocking to be configured as either internal or line (Internal
clocking is used when the POS interface is connected to another POS back-to-back or through DWDM,
while line clocking is required when the POS is connected to a SONET or SDH add/drop multiplexer).
WAH-PHY does not support clocking functionality.
Cisco ASR 1000 Series Aggregation Services Routers SIP and SPA Software Configuration Guide, Cisco IOS XE
Everest 16.5
OL-14127-17
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Overview of the Ethernet SPAs
Difference Between POS and 10GBASE-W