This is the index of the Class-of-Service profile applied to this dynamically-signaled tunnel, determining its priority and shaping treatment the same way as on a static tunnel. An admin cross-references this index against the CoS profile table to confirm the intended priority is applied, which is worth double-checking on dynamic tunnels specifically since a re-signal event could theoretically reset default settings if the tunnel is later recreated by automation. For example, a CoS profile index of 5 assigned here should be consistent with what the admin originally intended for this service, worth reverifying after any tunnel recreation event.