About this task
SBS Extensions and trunks count against the pool of available ports and trunks. You must consider whether SBS trunks that you add to an existing system increase traffic on the PSTN trunks. SBS trunk group members count against the pool of available IP trunks. SBS bearer calls usually use the same trunks as normal local and/or toll PSTN calls. Implementation of the SBS feature might require that you increase the quantity of trunks to the PSTN.