[nsp] Delay in MPLS PE lookup

[khiz]

Hi Gurus,
  I have implemented L3 MPLS VPN  in the foll  test scenario

CE-1 ---[PE-1]--|FR Switch|------WAN--------- |FR Switch|----[PE-2]--[CE-2]

Everything is working absolutely fine as far as  the MPLS L3 VPN functionalty is concerned.
My Concern is of the delay invloved in pinging from CE-1 to Ce-2
PE1 and Pe-2 are talking  MP BGP . There is no intermediate P routers for my network

Ping response from 
1> CE 1 to CE2 (with CE -1 directly connecting to CE-2 over the L2 Frame relay backbone using FR encapsulation) =  20 ms
2>Ce-1 to CE-2 (terminating  both the CE routers on the corresponding PE router) =  50 ms via the MPLS VPN 

Is this delay expected when moving from a layer 2 connectivty to an MPLS  connectivity given the fact that the PEs have to do L3 lookup and further label association

( PE 1 and PE2 still connect to each other via a FR PVC)

PE 1  and PE2 are Cisco 7513

Cheers
Knms