Planet GS-5220 Series, User Manual, Page: 557 / 568

User’s Manual of GS-5220 LCD Series
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computer systems. NTP uses UDP (datagrams) as transport layer.
O
OAM
OAM is an acronym for O peration A dministration and M aintenance. It is a protocol described in
ITU-T Y.1731 used to implement carrier Ethernet functionality. MEP functionality like CC and RDI
is based on this.
Optional TLVs.
An LLDP frame contains multiple TLVs. For some TLVs it is configurable if the switch includes the TLV in
the LLDP frame. These TLVs are known as optional TLVs. If an optional TLV is disabled the
corresponding information is not included in the LLDP frame.
OUI
OUI is the organizationally unique identifier. An OUI address is a globally unique identifier
assigned to a vendor by IEEE. You can determine which vendor a device belongs to according to
the OUI address which forms the first 24 bits of an MAC address.
P
PCP
PCP is an acronym for Priority Code Point. It is a 3-bit field storing the priority level for the 802.1Q
frame. It is also known as User Priority.
PD
PD is an acronym for P owered D evice. In a PoE> system the power is delivered from a PSE
(power sourcing equipment) to a remote device. The remote device is called a PD.
PHY