Very large fabric (VLF) engineering rules

Overview

This section describes the functionality and limitations relating to circuit pack/slot equipage and electrical/optical port availability when the VLF Main circuit packs are used. Use this section to help plan the use of circuit packs in the Function and Growth units of a shelf equipped with VLF Mains.

VLF circuit packs

Alcatel-Lucent 1665 DMXtend can be equipped with LNW84 or LNW141 VLF Main circuit packs. These circuit packs support true 0x1 configurations, in some cases resulting in double the overall port density for a given interface type.

The LNW84 main pack supports 8 PTM-based multi-rate (OC-3, OC-12, OC-48) ports and integrated STS and VT fabrics. The pack supports a maximum of 8 OC-3 interfaces, 8 OC-12 interfaces or 2 OC-48 interfaces. LNW84 also supports 16 DS1 and 3 DS3 interfaces. The LNW84 has a 170G non-blocking, STS fabric and a 20G VT fabric. VLF mains can support 10G per slot or 20G per function/growth group. The pack supports up to 10G of VT1.5s.

LNW141 supports one OC-192 interface and provides a total 60G of Input/Output interfaces. The LNW141 has 80G of usable STS-1 fabric and 10G of usable VT fabric. (The pack could support a 185 G STS-1 fabric and a 25G VT fabric with future tributary enhancements.)

Function Group D is general purpose slots and support all low-speed circuit packs (except the LNW7, LNW39, LNW391, LNW111, and LNW112).
Function Group G is referred to as the growth slot. Function Group G is general purpose slots and support all low-speed circuit packs (except the LNW7, LNW39, LNW391, LNW111, and LNW112).
VLF Mains provide up to 10G add/drop capacity to each low-speed slot in the shelf.
Function groups D and G have an STS add/drop capacity of 48 STS-1s.
Function Groups D and G support up to 48 ported TMUX DS3 or EC1 ports, 48 portless TMUX DS3 ports

However, there are certain restrictions with regard to which packs can reside next to each other in the same Function Unit or Growth slot. This section details these restrictions and provides general guidelines for circuit pack/slot equipage with the VLF Mains.

With VLF circuit pack in the Main slots, all switching and cross-connect functions are centralized on the STS and VT fabrics located on the VLF Main circuit pack. This is in contrast to shelves equipped with non-VLF Main circuit packs, where switching and cross-connection functions are distributed across the Main (high-speed) and tributary (low-speed) circuit packs/fabrics. When VLF Main circuit packs are used in conjunction with tributary packs that contain their own switch fabrics, the switch fabrics on the tributary circuit packs are automatically disabled.

Tributary circuit packs supported

The VLF Main circuit packs support all circuit packs supported by Alcatel-Lucent 1665 DMXtend shelf with the exception of the LNW7 28DS1 packs. Customers with VLF Mains requiring DS1 connectivity must employ the LNW8/LNW801 56DS1/E1 pack.

If the shelf is equipped with the full-length VLF LNW84 and LNW141 circuit pack, the half-length LNW39, LNW111, LNW112, and LNW391 circuit packs are not supported in the A and B slots.

Circuit pack compatibility for unprotected (0x1) configurations

The 0x1 capability allows compatible packs of different types to reside in the same low-speed group. Generally speaking, packs which use the rear-access electrical backplane connectors are not compatible with any other packs; that is, they cannot be installed in adjacent slots within the same group. This includes LNW7, LNW8, LNW801, LNW16, LNW18, LNW19B, LNW20, and LNW74 (unless both LNW74s are version S1:2 or later and in FX mode).

In the following list of compatibility guidelines, "Ethernet" includes Ethernet and SAN packs, "electrical" not modified by "TDM" refers to any pack that uses rear-access backplane connectors, and "TDM electrical" excludes Ethernet and Data packs. Note that "electrical" does not include Ethernet/Data packs using electrical PTMs.

0x1 circuit pack/slot compatibility guidelines

Listed below are circuit pack combinations that are incompatible for 0x1 configurations:

TDM electrical pack/any other pack
Any accepted pack/another TDM electrical pack
0x1-compatible Ethernet electrical pack/any other electrical pack

All other packs are compatible with each other for 0x1 configurations:

OLIU/different OLIU
OLIU/same OLIU
non-electrical 0x1-compatible Ethernet pack/non-electrical 0x1-compatible Ethernet pack
OLIU/0x1-compatible Ethernet pack (whether electrical or not)
electrical 0x1-compatible Ethernet pack/non-electrical 0x1-compatible Ethernet pack

Supported combinations of packs within a function/growth group

The table below summarizes the guidelines detailed above for 0x1 compatible pack combinations within the same group. An OLIU is in 0x1 mode when all ports in the OLIU are set to the 0x1 application.

Table 6-4: 0x1 compatible combinations

Circuit Pack Type
Slot 2	Slot 1
Slot 2	Rear Access	Mixed Front and Rear Access	Front Access
Rear Access	Not Compatible	Not Compatible	Compatible
Mixed Front and Rear Access	Not Compatible	Not Compatible	Compatible
Front Access	Compatible	Compatible	Compatible

Notes:

Front access packs include all OLIUs (Optical Line Interface Units), and the following Ethernet/Data packs: LNW63, LNW64, LNW73/73C, LNW87, and LNW170.

Ethernet equipage guidelines

If the Main slots are equipped with Very Large Fabric LNW84 or LNW141 OLIU circuit packs, the circuit packs in a Function/Growth group may be the same or different circuit pack type depending on the Slot Protection State.

For Ethernet circuit packs except the LNW170, the Slot Protection State parameter is fixed Unprotected. If the Slot Protection State is Protected and a 10/100 Ethernet circuit pack (other than the LNW170) is installed, the system reports an unexpected CP type alarm and service may be impacted.

The following combinations of circuit pack types are supported in Function/Growth Slot 1 and Slot 2 when the Slot Protection State is Unprotected.

Slot 2	Slot 1
Slot 2	LNW74 (S1:2 and later)	Other Front Access Circuit Packs¹
LNW74 (S1:2 and later)	Compatible²	Compatible
Other Front Access Circuit Packs¹	Compatible	Compatible

Notes:

This includes the LNW63, LNW64, LNW73/73C, LNW87, LNW170, LNW705, LNW785, and all low-speed OLIU circuit packs. The LNW7, LNW8, LNW16, LNW18, LNW19B, LNW20, LNW39, , LNW74 (S1:1), LNW391, LNW801, LNW111, and LNW112 are not 0x1 compatible.
The circuit pack Ethernet Mode parameter must be provisioned as FX to support LNW74 circuit packs in slot 1 and slot 2; otherwise, this configuration is incompatible. When pairing the LNW74 with another LNW74, ONLY the 8 SFP ports on each pack are usable, for a total of 16 SFP ports per function group. When mixing an LNW74 with any optical only pack, all 24 ports (16 electrical and 8 SFP ports) on the LNW74 are available.

If an incompatible circuit pack is installed in a Function/Growth slot, the system reports a CP not allowed - eqpt alarm.

The Slot Protection State parameter can be changed from Protected to Unprotected or from Unprotected to Protected.