how to Increase Number of TCP Connections for iOS?

[Complexi]

we're using an iOS configuration profile for its vpn connection. we are using "connect on demand". when going from wifi to cellular the vpn is unable to reconnect. however, the vpn stays connected just fine when going from cellular to wifi. we believe it has to do with the number of TCP connections being set to 1. how do we increase this number? thx.

VPN Server/VPN>SessionGet
SessionGet command - Get Session Information
Session name: SID-NAME@DOMAIN.COM-[L2TP]-9

Item |Value
------------------------------------------+-----------------------------------------------
Client IP Address |xx.xx.xx.xx
Client Host Name |xx-xx-xx-xx.name.domain.com
User Name (Authentication) |name@domain.com
User Name (Database) |*
VLAN ID |-
Server Product Name |SoftEther VPN Server (64 bit)
Server Version |4.10
Server Build |Build 9505
Connection Started at |2015-01-28 (Wed) 10:08:54
First Session has been Established since |2015-01-28 (Wed) 10:08:54
Current Session has been Established since|2015-01-28 (Wed) 10:08:54
Half Duplex TCP Connection Mode |No (Full Duplex Mode)
VoIP / QoS Function |Disabled
Number of TCP Connections |1
Maximum Number of TCP Connections |1
Encryption |Enabled (Algorithm: IPsec - AES-CBC (256 bits))
Use of Compression |No (No Compression)
Physical Underlay Protocol |Legacy VPN - L2TP
UDP Acceleration is Supported |No
UDP Acceleration is Active |No
Session Name |SID-NAME@DOMAIN.COM-[L2TP]-9
Connection Name |CID-4730
Session Key (160 bit) |2D0E01BA4539ABC2E0C90CC15BC804FB95B3B5E8
Bridge / Router Mode |No
Monitoring Mode |No
Outgoing Data Size |58,919 bytes
Incoming Data Size |79,413 bytes
Outgoing Unicast Packets |400 packets
Outgoing Unicast Total Size |57,537 bytes
Outgoing Broadcast Packets |6 packets
Outgoing Broadcast Total Size |1,382 bytes
Incoming Unicast Packets |336 packets
Incoming Unicast Total Size |79,329 bytes
Incoming Broadcast Packets |2 packets
Incoming Broadcast Total Size |84 bytes
Client Product Name |L2TP VPN Client
Client Version |4.10
Client Build |Build 9505
Client OS Name |L2TP VPN Client
Client OS Version |-
Client OS Product ID |-
Client Host Name |Johns-iphone-5s
Client IP Address |xx.xx.xx.xx
Client Port |1701
Server Host Name |xx.xx.xx.xx
Server IP Address |xx.xx.xx.xx
Server Port |1701
The command completed successfully.

[Nemesiz]

L2TP use UDP and more sessions does not influence the quality of connection.

[Complexi]

understood. thx.