Transceivers should have their own class instead of counting as modules

[jmbredal]

Transceivers such as GBICs are classified in ENTITY-MIB::entPhysTable as modules, and are therefore detected by NAV as such. We've received a lot of feedback that transceivers do not quite fit with NAV's module concept. A suggestion is that Transceiver should be a new model in NAV, and be exempt from the typical moduleUp/down alerts that NAV generates. The rationale for this is that these units are plugged in and out at will and failures would be detected using other means.

A suggest way around this in the collection phase is to use the entPhysTable hierarchy to "see" that a transceiver module is connected to a port instead of a slot, and call this module a transceiver, rather than a module.

Conversely, with some vendors/models, modules may actually connect to ports, such the case is with FEX modules on the Cisco Nexus platform. How can we differentiate between the two? This will likely be a difficult balance to strike.

---

Imported from Launchpad using lp2gh.

• date created: 2013-04-15T11:56:52Z
• owner: mbrekkevold
• the launchpad url was https://bugs.launchpad.net/bugs/1169154

[lunkwill42]

The essential code path to intervene in is in this method:

nav/python/nav/ipdevpoll/plugins/modules.py

Lines 99 to 112 in e6634e5

	def _process_modules(self, entities):
	# map entity indexes to module containers
	module_containers = {}
	modules = entities.get_modules()
	for ent in modules:
	entity_index = ent[0]
	device = self._device_from_entity(ent)
	module = self._module_from_entity(ent)
	module.device = device
	module_containers[entity_index] = module
	self._logger.debug("module (entPhysIndex=%s): %r", entity_index, module)
	return module_containers

A new method could be written to verify whether a module is a "proper" module or a transceiver, and filter out the transceiver ones.

[lunkwill42]

Also, essentially, I think this issue can be split into two parts:

1. Just stop classifying transceivers as modules
2. Add a new classification system to NAV

Number 2 might not be necessary. I would defer that decision to nav-ref.