Definition

trunk

Contributor(s): John Burke

A trunk is a communications line or link designed to carry multiple signals simultaneously to provide network access between two points. Trunks typically connect switching centers in a communications system. The signals can convey any type of communications data. A trunk can consist of multiple wires, cables or fiber optic strands bundled together to maximize the available bandwidth in a single physical cable, or it can consist of a single high-capacity link over which many signals are multiplexed.

A trunk can also consist of a cluster of broadcast frequencies, as in a trunked radio system that enables the sharing of a few radio frequency channels among a large group of users.

In telephony, trunks interconnect switching nodes, such as private branch exchanges (PBX) and central offices. In enterprise telephony, the transition from traditional time-division multiplexing (TDM) trunks to SIP trunks began around 2009 to use Voice over IP (VoIP) to connect a PBX to the internet.

Data networks use two types of trunks. First, trunks can carry data from multiple local area networks (LANs) or virtual LANs (VLANs) across a single interconnect between switches or routers, called a trunk port. Second, trunks can bond or aggregate multiple physical links to create a single, higher-capacity, more reliable logical link, which is called port trunking.

A trunk port marks frames with special identifying tags -- defined by IEEE standard 802.1Q for VLAN tags for Ethernet frames -- as they pass between switches, so each frame can be routed to its intended VLAN at the other end of the trunked link. Using port trunking to aggregate links is defined by IEEE standard 802.1aq and by the 802.1AX standard for LANs and metropolitan area networks, as well by various vendor-proprietary methods.

This was last updated in September 2016

Continue Reading About trunk

Dig Deeper on Telecommunication networking

Server virtualization and the impact on network configuration Server virtualization delivers sophisticated capabilities that affect performance, scaling and connectivity needs. Solutions have evolved from enabling partitioning of a single computer into multiple virtual servers to enabling virtual servers to be migrated between physical servers by managing a collection of servers as a single resource pool. This flexibility to migrate workloads and create virtual servers on demand has effects on the network that networking and data center professionals must prepare for. There are three major challenges that server virtualization poses for the network: an increase in the network addressing required, an increase in performance and throughput, and the inability to manage virtual networked relationships.

Join the conversation

2 comments

Send me notifications when other members comment.

Please create a username to comment.

Why are two types of trunks needed in networking?
Cancel
I think its one for analog and one for digital information transimitted in analog and then conveyed by digital conveter and received in digital form
Cancel

-ADS BY GOOGLE

Extensions de fichiers et formats de fichiers

Motorisé par:

SearchUnifiedCommunications

SearchMobileComputing

SearchDataCenter

SearchITChannel

Close