23,154 research outputs found
Duplicating RTP streams
Packet loss is undesirable for real-time multimedia sessions but can
occur due to a variety of reasons including unplanned network
outages. In unicast transmissions, recovering from such an outage
can be difficult depending on the outage duration, due to the
potentially large number of missing packets. In multicast
transmissions, recovery is even more challenging as many receivers
could be impacted by the outage. For this challenge, one solution
that does not incur unbounded delay is to duplicate the packets and
send them in separate redundant streams, provided that the underlying
network satisfies certain requirements. This document explains how
Real-time Transport Protocol (RTP) streams can be duplicated without
breaking RTP or RTP Control Protocol (RTCP) rule
Sending multiple RTP streams in a single RTP session
This memo expands and clarifies the behavior of Real-time Transport Protocol (RTP) endpoints that use multiple synchronization sources (SSRCs). This occurs, for example, when an endpoint sends multiple RTP streams in a single RTP session. This memo updates RFC 3550 with regard to handling multiple SSRCs per endpoint in RTP sessions, with a particular focus on RTP Control Protocol (RTCP) behavior. It also updates RFC 4585 to change and clarify the calculation of the timeout of SSRCs and the inclusion of feedback messages
Options for Securing RTP Sessions
The Real-time Transport Protocol (RTP) is used in a large number of
different application domains and environments. This heterogeneity
implies that different security mechanisms are needed to provide
services such as confidentiality, integrity, and source
authentication of RTP and RTP Control Protocol (RTCP) packets
suitable for the various environments. The range of solutions makes
it difficult for RTP-based application developers to pick the most
suitable mechanism. This document provides an overview of a number
of security solutions for RTP and gives guidance for developers on
how to choose the appropriate security mechanism
RTP control protocol (RTCP) extended report (XR) block for independent reporting of burst/fgp discard metrics
This document defines an RTP Control Protocol (RTCP) Extended Report
(XR) block that allows the reporting of burst/gap discard metrics
independently of the burst/gap loss metrics for use in a range of RTP
applications
Providing End-to-End Connectivity to SIP User Agents Behind NATs
The widespread diffusion of private networks in SOHO scenarios is fostering an increased deployment of Network Address Translators (NATs). The presence of NATs seriously limits end-to-end connectivity and prevents protocols like the Session Initiation Protocol (SIP) from working properly. This document shows how the Address List Extension (ALEX), which was originally developed to provide dual-stack and multi-homing support to SIP, can be used, with minor modifications, to ensure end-to-end connectivity for both media and signaling flows, without relying on intermediate relay nodes whenever it is possibl
A Framework for Aggregating Private and Public Web Archives
Personal and private Web archives are proliferating due to the increase in
the tools to create them and the realization that Internet Archive and other
public Web archives are unable to capture personalized (e.g., Facebook) and
private (e.g., banking) Web pages. We introduce a framework to mitigate issues
of aggregation in private, personal, and public Web archives without
compromising potential sensitive information contained in private captures. We
amend Memento syntax and semantics to allow TimeMap enrichment to account for
additional attributes to be expressed inclusive of the requirements for
dereferencing private Web archive captures. We provide a method to involve the
user further in the negotiation of archival captures in dimensions beyond time.
We introduce a model for archival querying precedence and short-circuiting, as
needed when aggregating private and personal Web archive captures with those
from public Web archives through Memento. Negotiation of this sort is novel to
Web archiving and allows for the more seamless aggregation of various types of
Web archives to convey a more accurate picture of the past Web.Comment: Preprint version of the ACM/IEEE Joint Conference on Digital
Libraries (JCDL 2018) full paper, accessible at the DO
Endpoint-transparent Multipath Transport with Software-defined Networks
Multipath forwarding consists of using multiple paths simultaneously to
transport data over the network. While most such techniques require endpoint
modifications, we investigate how multipath forwarding can be done inside the
network, transparently to endpoint hosts. With such a network-centric approach,
packet reordering becomes a critical issue as it may cause critical performance
degradation.
We present a Software Defined Network architecture which automatically sets
up multipath forwarding, including solutions for reordering and performance
improvement, both at the sending side through multipath scheduling algorithms,
and the receiver side, by resequencing out-of-order packets in a dedicated
in-network buffer.
We implemented a prototype with commonly available technology and evaluated
it in both emulated and real networks. Our results show consistent throughput
improvements, thanks to the use of aggregated path capacity. We give
comparisons to Multipath TCP, where we show our approach can achieve a similar
performance while offering the advantage of endpoint transparency
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