Cisco 15327 - Manual (Page 422)

24-14
Ethernet Card Software Feature and Configuration Guide, R7.2
Chapter 24 CE-100T-8 Ethernet Operation
CE-100T-8 VCAT Characteristics
CE-100T-8 Pool Provisioning Rules
All VCAT circuit members must be from the same pool. One of the four memory pools is reserved for
the low-order VCAT circuits if sufficient bandwidth exists to support the high-order circuits in the
remaining three pools. The high-order CCAT circuits use all the available capacity from a single memory
pool before beginning to use the capacity of a new pool. The memory pools are allocated alternatively
for the first three high-order VCAT circuits if the pools have the sufficient bandwidth to support the
requested circuit size. To help prevent stranding bandwidth, provision your high-order VCAT circuits
first to distribute them evenly.
CE-100T-8 VCAT Characteristics
The ML-100T-8 card and the CE-100T-8 card (both the ONS 15310-CL version and the ONS 15454
SONET/SDH version) have hardware-based support for the ITU-T G.7042 standard Link Capacity
Adjustment Scheme (LCAS). This allows the user to dynamically resize a high order or low order VCAT
circuit through CTC or TL1 without affecting other members of the VCG (errorless).
To enable end-to-end connectivity in a VCAT circuit that traverses through a third-party network, you
must create a server trail between the ports. For more details, refer to the "Create Circuits and VT
Tunnels" chapter in the Cisco ONS 15454 Procedure Guide.
The ONS 15454 SONET/SDH ML-Series card has a software-based LCAS (SW-LCAS) scheme. This
scheme is also supported by both the ML-100T-8 card and the CE-100T-8 (both the ONS 15310-CL
version and the ONS 15454 SONET/SDH version), but only for circuits with the other end terminating
on a ONS 15454 SONET/SDH ML-Series card.
The CE-100T-8 card allows independent routing and protection preferences for each member of a VCAT
circuit. The user can also control the amount of VCAT circuit capacity that is fully protected,
unprotected, or uses Protection Channel Access (PCA) (when PCA is available). Alarms are supported
on a per-member as well as per virtual concatenation group (VCG) basis.
Note The maximum tolerable VCAT differential delay for the CE-100T-8 is 48 milliseconds. The VCAT
differential delay is the relative arrival-time measurement between members of a VCG.
CE-100T-8 POS Encapsulation, Framing, and CRC
The CE-100T-8 uses Cisco EoS LEX (LEX). LEX is the primary encapsulation of ONS Ethernet cards.
In this encapsulation, the protocol field is set to the values specified in Internet Engineering Task Force
(IETF) Request For Comments (RFC) 1841. The user can provision frame-mapped generic framing
procedure (GFP-F) framing (default) or high-level data link control (HDLC) framing. With GFP-F
framing, the user can also configure a 32-bit CRC (the default) or no CRC (nond). On CTC go to CE
card view and click the Provisioning >pos ports tab, to see the various parameters that can be configured
on the POS ports, see
“Table 2-3CTC Display of POS Port Provisioning Status” task on page 2-3 .
Various parameters like, admin state, service state, framing type, CRC , MTU and soak time for a port
can be configured here . When LEX is used over GFP-F it is standard Mapped Ethernet over GFP-F
according to ITU-T G.7041. HDLC framing provides a set 32-bit CRC. For more details about the
interoperability of ONS Ethernet cards, including information on encapsulation, framing, and CRC, see
the
“POS on ONS Ethernet Cards” chapter.
The CE-100T-8 card supports GFP-F null mode. GFP-F CMFs are counted and discarded.