Cable Types

Added in version 3.2.0

While the definition and usage of cable types is optional when modeling simple point-to-point cables, cable types are primarily required when modeling breakout cables in Nautobot. A cable type defines the physical connectivity of cables using this type, including the number of connectors at each side, the number of internal lanes within the cable, and the mapping between connectors and lanes.

When initially installed or upgraded to v3.2.0 or later, Nautobot automatically creates a number of pre-defined basic cable types by default. These are not protected records and will not be auto-recreated later; feel free to use, modify, or delete them as suits your needs. You are also free to create as many custom cable types as you like.

Fields

A cable type has the following fields:

Field	Type	Required	Description
name	string	Yes	Unique name for the cable type
a_connectors	integer	Yes	Number of physical connectors on the "A" side of the cable
b_connectors	integer	Yes	Number of physical connectors on the "B" side of the cable
total_lanes	integer	Yes	Total number of logical lanes within the cable
mapping	JSON	Yes	Array of total_lanes entries describing the relations among a_connectors, b_connectors, and individual lane definitions within the cable
description	string	No	Descriptive details
manufacturer	Manufacturer	No	Manufacturer information
part_number	string	No	Part number
has_embedded_transceivers	Boolean	No	Informational - whether transceivers such as SFPs are built in to the cable
is_shuffle	Boolean	No	Informational - whether the lane mapping is non-linear, polarity-shuffled, etc.
strands_per_lane	integer	No	Informational - number of physical strands per logical lane
polarity_method	string (enum)	No	Informational - fiber polarity method, if relevant. One of straight-through, reversed, pair-reversed, or other.

Validation

• If a cable type has differing a_connectors and b_connectors values, the A side must represent the "trunk" end of the cable (in other words, a_connectors <= b_connectors is enforced). This is to avoid inadvertent definition of redundant symmetric cable types (such as both a "1x4 breakout" and a "4x1 breakout").
• The total_lanes must be evenly divisible by both a_connectors and b_connectors.
• The mapping must contain exactly total_lanes entries, each of which has a valid and unique set of a_connector, a_position, b_connector, and b_position values (as well as an optional label value). Refer to the Breakout Cables feature guide for examples of valid mappings.
• An existing cable type that is referenced by existing cables may not change its a_connectors, b_connectors, total_lanes, strands_per_lane, or mapping values as doing so would invalidate those cables.
• An existing cable type that is referenced by existing cables may not be deleted.

Properties

Property	Type	Description
a_positions	integer	Number of lane positions per "A" side connector (total_lanes / a_connectors)
b_positions	integer	Number of lane positions per "B" side connector (total_lanes / b_connectors)
total_strands	integer	Number of physical strands within the cable (total_lanes x strands_per_lane)
is_breakout	Boolean	Whether this is a breakout cable (b_connectors > a_connectors)
is_multi_connector	Boolean	Whether this is a multi-connector cable or a simple point-to-point one
trunk_end	string	"A" for breakout cables, None for non-breakout cables