Layer 1
In Layer 1 operating mode every bit is encapsulated into an IP packet. The size and frequency of the IP packets can be set with data bit rates from 2.4 to 250 Kilobits per second. Latency minimization is accomplished with multidimensional adaptive clock configurations. A configured number of incoming packets are buffered in order to compensate for the packet delivery jitter introduced by the network. The size of this buffer needs to accommodate the peak amount of jitter.

HDLC Over IP
In Layer 2 operating mode HDLC Data frames clocked at 2.4 to 250 Kilobits, such as those used by Wide Area Networking protocols PPP and Frame Relay or proprietary Data Links, are transported within IP packets as HDLC over IP. The latency introduced is dependent upon the clocking rate and the HDLC frame size. Minimum latency is obtained by maximizing the clock rate and minimizing the MTU. HDLC Over IP frames are directly sent out the Serial interface since Clock synchronization is not required. WAN security provisioning, such as firewalling, is maintained.

IP•Tube RS232 Standard Features

Dual LAN Interfaces

All IP•Tube RS232 models ship with dual 10/100BaseT Ethernet LAN ports. The dual Ethernet interfaces provide for: 

• Management interface on LAN port 2 when LAN port 1 is connected to a VPN tunnel 
• The LAN ports can be configured to support connections over 2 Asymmetrical bandwidth    links 
• Alternator Option for load balanced SDSL interconnects 
• Protector Option for Redundant Packet Path connections with Constant or Switch Over  Criteria

Assured Delivery Protocol
In order to assure high quality communications over links with intermittent or noisy performance, such as Wireless or Broadband over Power Line, the IP•Tube RS232 employs Engage’s robust Assured Delivery Protocol with the following benefits: 

• Packet out of sequence detection and re-sequencing
• Duplicate skipping,
• Lost packet retransmissions with configured delay.

Assured Delivery Protocol

In order to assure that circuits are extended over connections with fault tolerance the IP•Tube RS232 has as a standard capability an Assured Delivery Protocol that supports high performance full duplex real time data. The protocol has packet out of sequence detection and re sequencing, duplicate skipping, and real time lost packet retransmission with configured delay.