Specifications

Planning and Engineering Guide, Release TR5.0.x/TN6.0.x 21
STS-3c/AU-4 Contiguous concatenation of 3 STS-1
synchronous payload envelopes (SPE)
(STS-3c)
Administrative Unit Level 4 (AU-4)
STS-3c/VC-4 Contiguous concatenation of 3 STS-1
synchronous payload envelopes (SPE)
(STS-3c)
VC level 4 (VC-4)
STS-12c/VC-4-4c Contiguous concatenation of 12 STS-1
SPEs (STS-12c)
Contiguous concatenation of 4 VCs at
Level 4 (VC-4-4c)
UPSR/SNCP Unidirectional Path Switched Ring Subnetwork Control Protocol (SNCP)
Ring
VT/LO Virtual Tributary (VT) Low Order (LO)
VT/VC VT Virtual Container (VC)
VT/TU VT Tributary Unit (TU)
VTX/VCX VT Cross-connect (VTX) VT Cross-connect (VCX)
Wideband DCS Wideband Digital Cross-connect
System (WDCS)
n/a
Table 2 SONET and SDH Comparative Terminology (continued)
Term SONET Network SDH Network