Bandwidth Limitation on Gre tunnel

[Kangalala]

Hi guys,

I have a BGP point to point connection over a 100Mbps link between Branch office and Main office, connection via ISP.

I have set up under two cisco routers 2801 with advance security ios a GRE tunnel running ospf protocol so I can share multicast traffic for streaming between the two sites but I'm only able to get 6 Mbps out of the tunnel between the sites. I have configured PIM Sparce-mode multicast to carry video traffic over the tunnel.

Is there a limit over the GRE tunnel, could it be MTU or perhaps other issues anybody can help me resolve this issue guys?

Is the limitation with certain equipment or is it adjustable with configuration because I'm not able to more than 6 Mbps on a 100Mbps ISP dedicated link? I mainly use it for multicast video traffic over the Wan Link from a branch office to HQ.

[Joseph W. Doherty]

What's the CPU utilization look like on the 2801s when you're doing your 6 Mbps across the tunnel?

(NB: fragmentation will load an ISR's CPU, and video probably doesn't do PMTUD [nor will it likely be impacted by adjust MSS, if used].  If you do have a fragmentation issue, you might need to reduce MTU on the multicast source host interface.)