I'm looking for design/scale recommendations for intra-site routing when provisioning a branch office. Specifics for this example:
- multiple VLANs/subnets at each branch (voice, video & data)
- Cisco ISR router (voice gateway) at the edge, providing WAN routing and PSTN termination outside of the branch
- any number of switch ports internally (which leads to my question)
I know the WAN router is capable of providing all routing for the branch subnets, but at what point would proper design recommend off-loading this burden to a more capable device (an internal L3 switch), rather than passing everything to a box that was built to provide services, moreso than packet-switching speed, especially for sites provisioned with Gigabit Ethernet endpoints?
I haven't yet found a document w/ specifics around where the edge router might not be the recommended router for the branch, and when a L3 switching front-end would be the better choice.
Thank you, and reference links/docs are always appreciated!