[Serusers] 483 too many hops

Hi, I am using the standard code for sanity check in the routing script: if (!mf_process_maxfwd_header("10")) { sl_send_reply("483", "Too Many Hops"); break; }; if (msg:len > max_len) { sl_send_reply("513", "Message Overflow"); break; }; And once I start the SER, after 10 minutes, there are around 10% of the users get "483 Too Many Hops" from SER upon re-registration. Subsequently SER is binding them out as their register sip messages are not received in time. Is there any way to eliminate this issue? Will it be routing script problem? Thanks. Regards, Chia