Ip Packet Payload Compression; Inbound Header Compression; Performance Enhancing Proxy (Pep V3); Tcp Spoofing - Hughes HX System System Overview

IP packet payload
Inbound header compression A standard TCP/IP header is 40 bytes per packet, and most of that
Performance Enhancing Proxy
Chapter 6 • IP features
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IP packet payload compression is a feature of the performance
compression enhancing proxy (PEP). It compresses grouped packets to achieve
compression ratios of up to 12;1. For more information, see PEP
and TCP payload compression on page 60.
information is redundant for a given session. Header compression
suppresses any redundant information, reducing the bandwidth
required for the header. This compression capability requires that
a large number of the fields either do not change, or change only
in expected ways. Inbound header compression:
• Compresses TCP/IP headers from 40 bytes to 10-12 bytes
• Reduces bandwidth by 15-20%
Multiple types of IP headers can be compressed, including:
• IP headers
• UDP headers
• RTP headers
• PBP headers
The performance-enhancing proxy (PEP) feature improves the
(PEP V3) throughput and response time of Internet applications while
minimizing required bandwidth. The HX satellite routers
implement the PEP feature, which includes bidirectional TCP
spoofing, data and header compression, IP prioritization,
acknowledgement reduction, and message multiplexing.
The PEP feature can be disabled if required.

TCP spoofing

TCP spoofing uses local devices in place of devices on the other
side of the satellite link to respond to TCP overhead messages.
For example, in the PEP TCP spoofing scheme, the HX gateway
acknowledges packets from the enterprise network, while satellite
routers acknowledge packets sent to the enterprise network from
the remote LAN. PEP also spoofs the three-way TCP connection
handshake and connection terminations.
The Hughes PBP (PEP backbone protocol) is used in the space
segment. It multiplexes multiple TCP connections for transport
across the satellite link, thus reducing delays and maximizing
bandwidth efficiency.

PEP and TCP payload compression

PEP can compress packet payloads to achieve savings in data
transmission time. PEP uses the V.44 lossless compression