Nortel Networks 3500 User Manual
Operation, administration, and maintenance (OAM) features 2-99
Planning and Ordering Guide—Part 1 of 2 NTRN10AN Rel 12.1 Standard Iss 1 Apr 2004
Generic Framing Procedure and Virtual Concatenation support
The OPTera Metro 3500-based implementation for point-to-point Ethernet and
storage connectivity services uses the GFP and VCAT standards.
storage connectivity services uses the GFP and VCAT standards.
Generic Framing Procedure (GFP)
GFP (Generic Framing Procedure) is an ITU standard (G.7041) which
describes a flexible mapping technique for transparent transport of multiple
protocols in SONET.
describes a flexible mapping technique for transparent transport of multiple
protocols in SONET.
The GFP provides an efficient mechanism for Gigabit Ethernet (GE) and Fibre
Channel (FICON and FC-100) transport over a SONET core network via
efficiently mapping varying client signals into SONET STS frames.
Channel (FICON and FC-100) transport over a SONET core network via
efficiently mapping varying client signals into SONET STS frames.
GFP defines two different implementations: Transparent GFP (GFP-T), for
byte-oriented data streams that require low latency transmission, and
Framed-mapped GFP (GFP-F), which maps one frame or packet of client
signal in one GFP frame. The GFP-T mapping scheme is transparent, as
control characters are not interpreted but generally encoded and transmitted.
The far-end GFP client must however have knowledge of the client signal type
in order to correctly handle client-specific issues. GFP-T is recommended for
SAN service. GFP-F processes client signal data streams on a Protocol Data
Unit (PDU) basis and maps these streams into GFP-F frames one packet at a
time. GFP-F is recommended for Ethernet services as it provides flow control
capability as well as performance monitoring (Operational Measurements
(OM) and Performance Monitoring (PM)).
byte-oriented data streams that require low latency transmission, and
Framed-mapped GFP (GFP-F), which maps one frame or packet of client
signal in one GFP frame. The GFP-T mapping scheme is transparent, as
control characters are not interpreted but generally encoded and transmitted.
The far-end GFP client must however have knowledge of the client signal type
in order to correctly handle client-specific issues. GFP-T is recommended for
SAN service. GFP-F processes client signal data streams on a Protocol Data
Unit (PDU) basis and maps these streams into GFP-F frames one packet at a
time. GFP-F is recommended for Ethernet services as it provides flow control
capability as well as performance monitoring (Operational Measurements
(OM) and Performance Monitoring (PM)).
3
60950
6095
2
91430
9143
1
See
182860
18286
Note 1:
When measuring round trip delay, please be aware that round trip latency measurement
(RTDELAY) returns the network latency to an accuracy of +/- 1 ms.
Note 2:
Approximation assuming no network element propagation delays and a 5 microsecond /
kilometer fiber propagation delay.
Note 3:
For Contiguous Concatenation the extended reach supported distances are:
STS1 = 18266 kms
STS3c = 5908 kms
STS12c = 1477 kms
STS24c = 987 kms
STS3c = 5908 kms
STS12c = 1477 kms
STS24c = 987 kms
Table 2-20 (continued)
Fibre Channel extended reach sample distances
Fibre Channel extended reach sample distances
STS1-nv
Round Trip Delay
(
µs)
See
Note 1
Distance
(kms)
See
Note 2
STS3c-nv
Round Trip Delay
(
µs)
Distance
(kms)
See
Note 2