ESMI Change Request: Add SCTP as optional IP transport ... - ATIS

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Emergency Services Interconnection Forum

(ESIF)


Emergency Services
Network

Interface
s

Task Force
(“Task Force 34”)



Contribution
Title:

SCTP
A
s
O
ptional
T
ransport for ESMI


Contribution Number:

ESMI
-
0
58


Source:

TeleCommunication Systems, Inc
. (TCS)

2401

Elliott Ave, 2nd Floor

Seattle, WA

98121


Technical Contact
(
s
)
:



Name:

Yinjun Zhu

Phone
: (
206)792
-
2892

Email:

yzhu@telecomsys.com



Abstract:


Like TCP, Stream Control Transmission Protocol (SCT
P, defined in RFC2960) provides a
reliable transport service, ensuring that data is transported across the network without error
and in sequence. In addition, SCTP also provides a number of functions that are beneficial
to ESMI interface, e.g. message orie
nt transport, multi
-
streaming, multi
-
homing etc. SCTP is
widely used in the telecom industry.


SCTP may be supported as
the
transport protocol

of

ESMI interface.


Recommendation:


Add
SCTP as an optional IP transport protocol for ESMI.







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ii


6.2
High Level
Requirements

6.2.1
CESE to ESNet Network Requirements

ESMI.Network.0100
-
0100

The Emergency Services Messaging Interface (ESMI) shall
support TCP/IP
as transport protocol

between CESEs and RGs
, in addition
SCTP
should

be supported as tr
ansport protocol
.

Rationale:

Both
TCP/IP

and SCTP

support

a large collection of readily available techniques and
technologies for implementing the ESMI and additional layered on features and
applications. It is assumed that this interface will require a minimum tra
nsport layer
speed and is not supported over existing legacy asynchronous 1200/9600 bps links.
More advanced transport speeds are expected to be required as additional
information sources, services, and interaction models are introduced to the PSAP or
oth
er CESE entity. The number of call taker positions supported per ALI retrieval
submittal rate and ALI response model (wireless can lead to multiple responses) will
ultimately lead to situational dependent engineering analysis of required transport
bandwid
th. Physical links should be engineered for acceptable transport latency for
each expected application scenario being implemented with the ESMI (e.g., ALI
delivery).
Like TCP, Stream Control Transmission Protocol
(
SCTP
, defined in
RFC2960)

provides a reli
able transport service, ensuring that data is transported
across the network without error and in sequence.

In addition, SCTP also provides a
number of functions that

are beneficial to ESMI interface, e.g.
message orient
transport,
multi
-
streaming, multi
-
h
oming

etc.
SCTP
is

widely used in t
he t
elecom
industry
.

ESMI.Network.0200
-
0100

The CESE shall be designated as the
client and the RG shall be
the
server.

Rationale:

It is the responsibility of the CESE to initiate the connection to the RG at the transpo
rt
level. At the application level the CESE and the RG operate as peers since messages
are initiated from either one.

6.2.2
Protocol Framework

ESMI.Network.0400
-
0100

While initial implementations may only incorporate text
transmission between the CESE and
RG, the ESMI and the corresponding
network shall be capable of supporting the transmission of images, video, high
resolution graphics, voice, and other capabilities through the same channel or
additional channels.

Rationale:

For many services simple transmission of t
ext is sufficient. However, one of the
significant advantages of this architectural concept is the opportunity to offer services
that extend the communication to all types of media. If the minimum rate, i.e. 56kbs, is
deployed these higher bandwidth servic
es will be severely limited.

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iii

ESMI.Network.0500
-
0100

Connections between the CESE and RG shall be secured TCP/IP
or SCTP/IP
socket connections such that advanced
authorization,
authentication
and security features can be implemented.

Rationale:

TCP/IP sockets allow ma
naged and monitored point to point application level transport.
Such techniques easily extend to support strong authentication, server authentication,
and content encryption. TCP/IP sockets can be established and maintained over a
relative long period of

time, thus, spreading the overhead of establishing and
authenticating the connection over a period of time.