Network Glossary O

OAM See Operation, Administration, and Maintenance.

OFDM See orthogonal frequency division multiplexing.

offset list A Cisco IOS configuration tool for RIP and EIGRP for which the list matches routes in routing updates, and adds a defined value to the sent or received metric for the routes. The value added to the metric is the offset.

one-time password Defined in RFC 2289, a mechanism by which a shared key and a secret key together feed into a hash algorithm, creating a password that is transmitted over a network. Because the shared key is not reused, the hash value is only valid for that individual authentication attempt.

OOF See Out of Frame.

Operation, Administration, and Maintenance A term referring to the processes and bits in the data stream used to manage the Telco TDM hierarchy.

optional nontransitive A characterization of a BGP path attribute in which BGP implementations are not required to support the attribute (optional), and for which if a router receives a route with such an attribute, the router should remove the attribute before advertising the route
(nontransitive).

optional transitive A characterization of a BGP path attribute in which BGP implementations are not required to support the attribute (optional), and for which if a router receives a route with such an attribute, the router should forward the attribute unchanged (transitive).

ORIGIN A BGP path attribute that implies how the route was originally injected into some router’s BGP table.

ORIGINATOR_ID Used by RRs to denote the RID of the iBGP neighbor that injected the NLRI into the AS.

orthogonal frequency division multiplexing A technology that sends a high-speed data stream over multiple subcarriers simultaneously. It is highly immune to multipath interference. 802.11a and 802.11g specify the use of OFDM.

OTP See one-time password.

Out of Frame A T1 alarm state that occurs when the receiver can no longer consistently identify the frame. See LOF.

outer label An MPLS term referring to the first of several labels when an MPLS-forwarded packet has multiple labels (a label stack).

Outside Global address A NAT term describing an IP address representing a host that resides outside the enterprise network, with the address being used in packets outside the enterprise network.

Outside Local address A NAT term describing an IP address representing a host that resides outside the enterprise network, with the address being used in packets inside the enterprise network.

overlapping VPN An MPLS term describing designs in which one or more MPLS customer sites can be reached from multiple other VPNs.

overloading Another term for Port Address Translation. See PAT