2*AR28-31 between two cities connected to each other with E1 channel. CRBT VXML Server connected to 2*AR28-31 and can ping each other.
When between CRBT VXML Server was enabled load-balancing
commmunication was fault between Load balance VXML Server which connected to AR28-31.
The routing table was checked and found no problem in configuration.
The version of 2*AR28-31(Version 3.40, Release 0017) is same which was also checked and found OK.
In AR28-31 we do not have to configure anything extra for support load balancing and just after making "undo arp check enable" - under system view and the problem was solved.