All Rights Reserved © Alcatel-Lucent 2007, Albrecht Schwarz Sigtran Introduction Disheng.chen

All Rights Reserved © Alcatel-Lucent 2007, Albrecht Schwarz

Sigtran Introduction

Disheng.chen

All Rights Reserved © Alcatel-Lucent 2007,

Agenda

■SCTP ■ M3UA■UI


SCTP VS TCP

file 1record 0

file 1record 1

file 2record 0

file 2record 1

file 3record 0

file 3record 1

file 2record 0

file 2record 1

TCP connection

SCTP association

file 1record 0

file 1record 1

file 3record 0

file 3record 1 file 3

record 1

file 3record 0

file 2record 1

file 2record 0

file 3record 1

file 3record 0

file 2record 1

file 2record 0

file 1record 1

file 1record 0

file 1record 1

file 1record 0

SCTPEndpoint

A

SCTPEndpoint

B

TCPEndpoint

A

TCPEndpoint

B

buffered

buffered received

received

Stream 0

Stream 1

Stream 2


SCTP Multihoming

MGC

10.11.23.14 10.11.23.16

10.11.23.15 10.11.23.17

Path2 Path1

Path3

SG

2905

Path0

2905


SCTP vs TCP

■SCTP was designed to overcome the TCPhead-of-line blocking problem with…

● …unordered delivery feature ● … multi-streaming

● … multi-homing

■ Reordering is done based on stream sequence numbers (SSN) separately for each stream

■Number of incoming and outgoing streams is negotiated when association is established


SCTP Terminology (RFC2960, RFC3309, RFC4960)

•Transport Address a SCTP port + an IP address (IPV4/IPV6)

•Endpoint logical sender/receiver. a source port + one or more source IP + a

dest port + one or more dest IP. •Association

a Connection between 2 endpoints. •Path

a route taken from one host to a specific destination transport address of its peer end point. a source port + a source IP + a dest port + a dest IP.

•Stream a unidirectional logical channel, usually with in-sequence delivery.

Unordered delivery also possible. •Chunck

A unit of information within an SCTP packet, consisting of a chunk header and chunk-specific content.


SCTP Endpoint

Own_ip:10.11.23.15 10.11.23.14Remote_ip: 10.11.23.16 10.11.23.17Own port: 2905 Remote port:2905

remote_ip:10.11.23.15 10.11.23.14own_ip: 10.11.23.16 10.11.23.17Own port: 2905 Remote port: 2905

MGCSG

Associaton

EndPoint1 EndPoint

2


SCTP Packet Format

Source Port

Dest.Port

Checksum(CRC32C)

32Bit

Verification Tag

Type Flags Length

Chunk specific Data

Type Flags Length

Chunk specific Data

SCTP Common

Header(12 Bytes)

SCTP Chunk 1

(>=4 Bytes)

IP-Proto:Ox84

SCTP Chunk n(>=4 Bytes)

… …


SCTP important chunck types

Association Setup Initiation(INIT):1 Initiation Acknowledgement(INIT ACK):2 State Cookie(COOKIE ECHO):10 Cookie Acknowledgement(COOKIE ACK):11

Association Teardown Abort(ABORT):6 Shutdown(SHUTDOWN):7 Shutdown Ackn. (SHUTDOWN ACK):8 Operation Error(ERROR):9

Data Transmission: Payload Data(DATA):0 Selective Acknowledgement(SACK):3

Path Management: Heartbeat Request(HEARTBEAT):4 Heartbeat Ackn. (HEARTBEAT ACK):5


SCTP data chunck

■Data chunk carries two sequence numbers: ●32 Bit Trans mission Sequence Number (TSN) used solely for reliable delivery ●16 Bit Stream Sequence Number (SSN) used for reordering within a stream■Flags may be set for:

●Segmentation ●Unordered Delivery■ Payload Protocol ID can be used to identify user application1: IUA; 2: M2UA; 3: M3UA; 4: SUA; 5: M2PA; 6: V5UA; 10: DUA

32 Bit

Flags: U B E

Type Length

TSN

Stream ID

Stream SN

Payload Protocol ID

User Data

The (U)nordered bit, if set to '1', indicates that this is anunordered DATA chunk, and there is no Stream Sequence Numberassigned to this DATA chunk. Therefore, the receiver MUST ignorethe Stream Sequence Number field.


SCTP Association setup

sctp_restart_ok.cap

Host A Host B

Resource Allocation

INIT (List of IP addresses,A1,A2,… ）

INIT ACK (Cookie, List of addresses,B1,B2, …)

COOKIE ECHO (Cookie)

COOKIE ACK


SCTP Association Teardown (Abort)

sctp_ab_ab.cap

■Two methods for termination of an association have been defined: ●Association Abort (see below) ●Graceful Termination

Host A Host B

associationis gone !

ABORT(32 bit verification)


SCTP Association Teardown (Graceful)

■Standard covers also all the pathological casesHost A Host B

Flush Queues

SHUTDOWN

SHUTDOWN ACK

SHUTDOWN COMPLETE

m3ua_sct_sh_abort.cap

Flush Queues

CLOSE


SCTP stream concept

Streams

Streams

TGW

T1/E1

SS7 Links

IP

Asso

cia

tion

Asso

cia

tion

Streams

Streams

IP

Asso

cia

tion

TGW

T1/E1

SS7 Links A

ssocia

tion

MGC

ASP

ASP

For IUA/M2UA, Interface Identifier has a one to one relationship with a SS7 Link. Each message received is routed to the corresponding Stream.


SCTP stream concept

P1 P2 P3 P4SCTP User

Processes1

1

2

17

18

19

5

2 3 16 7

SCTPStreamQueues

New SCTPPacket


SCTP Multihoming

AS 0

IP address a’IP address aASP a

IP address b’IP address bASP b

IP address c’IP address cASP c

AS 1

IP address x’IP address x ASP x

IP address y’IP address y ASP y

IP address z’IP address z ASP z

SignallingGateway

= multi-homing

SCTP associations


SCTP Multihoming

■each host selected one path as primary path

●say:A1-B1 and B3-A2 ■ carries main data load (except retransmissions) ■ idle paths are heart-beaten (~once in 30 secs) ■ path states can be active or inactive


SCTP Multihoming

■one path fails:■ A experiences ratrans mission timeouts

■ A increases a path error counter

■ so does B with its hearts-beats (slower!)■ std. threshold for setting path inactive:5

■ A will mark path to B1 inactive■retrans missions will go to another path(B2,B3)


Agenda



AS and ASP

call serve

r

Web server

Media Resource

Server

Vidio Server

Application Server (AS) : A logical entity serving a specific application instance.

Application Server Process (ASP) - A process instance of an Application Server.


Sigtran Framework Architecture (one scenario)

Sigtran


SP A(PC: 1-1-1)

ASP1(PC: 2-2-2)

SP B(PC: 3-3-3)

SS7 link

Germany

France A7510

SCTP association

User Data

MTP3 Route table:Number of routes : 4-------------------------------------------------------------------------------Route-ID Network-ID DPC Direction(*) Protocol Cmblinkset-ID Restart------------------------------------------------------------------------------- 0 0 1-1-1 Down ITU 0 ITU92 1 0 3-3-3 Down ITU 2 ITU92 2 0 2-2-2 Up ITU 1 ITU92 3 0 4-4-4 IP ITU 3 ITU9-------------------------------------------------------------------------------

OPC 1-1-1 DPC 2-2-2OPC 1-1-1 DPC 2-2-2

MTP3

Cmblinkset 0

Cmblinkset 2

M3UA Route Filter Parameter (for M3UA packets sent to AS)---------------------------------------------------------AS OPC OPC-Mask DPC DPC-Mask SLS SLS-Mask SIO SIO-Mask 1 1-1-1 14 2-2-2 0 0 4 0 4 2 3-3-3 14 4-4-4 0 0 4 0 4

ASP4(PC: 4-4-4)

ASP2(PC: 2-2-2)

ASP1

ASP2

AS1

ASP4 AS2

M3UA Routing based on DPC (same rule can be applied to OPC)

M3UA

OPC 1-1-1 DPC 4-4-4

OPC 1-1-1 DPC 4-4-4

OPC-Mask=14 means ignore the

OPC field


SP A(PC: 1-1-1)

ASP1(PC: 2-2-2)

SP B(PC: 3-3-3)

SS7 link

Germany

France A7510

SCTP association

ISUP

MTP3 Route table:Number of routes : 4-------------------------------------------------------------------------------Route-ID Network-ID DPC Direction(*) Protocol Cmblinkset-ID Restart------------------------------------------------------------------------------- 0 0 1-1-1 Down ITU 0 ITU92 1 0 3-3-3 Down ITU 2 ITU92 2 0 2-2-2 Up ITU 1 ITU92 3 0 4-4-4 IP ITU 3 ITU92 4 0 7-9-8 down ITU 0 ITU92

-------------------------------------------------------------------------------

OPC 1-1-1 DPC 2-2-2OPC 1-1-1 DPC 4-4-4

MTP3Cmblinkset 0

Cmblinkset 2


ASP4(PC: 5-5-5)

ASP2(PC: 2-2-2)ASP1

ASP2

AS1 ISUP

ASP4 AS2 SCCP

M3UA Routing based on Service Type

M3UA

SCCP

Question: if DPC-Mask=0 for AS1 and AS2 , what will happen?

OPC 1-1-1 DPC 2-2-2

DPC-Mask=14 means ignore the

DPC field

Down: to tdmUp: to IPIP: to IP

7-9-8


SP A(PC: 1-1-1)

SP B(PC: 3-3-3)

SS7 link

Germany

France A7510

SCTP association

ISUP


OPC 1-1-1 DPC 2-2-2OPC 1-1-1 DPC 5-5-5

MTP3Cmblinkset 0

Cmblinkset 2


ASP2(PC: 2-2-2)

5-5-5ASP2

AS1 ISUP

M3UA Routing based on Service Type

M3UA

SCCP

Question: if DPC-Mask=0 for AS1 and AS2 , what will happen?

DPC-Mask=14 means ignore the

DPC field

Down: to tdmUp: to IPIP: to IP


SP A(PC: 1-1-1) SGW(PC: 2-2-2)

MGC(PC: 2-2-2)

SP B(PC: 3-3-3)

SS7 link

Germany

France

A7510

SCTP association

ISUP

Route table:Number of routes : 5-------------------------------------------------------------------------------Route-ID Network-ID DPC Direction(*) Protocol Cmblinkset-ID Restart------------------------------------------------------------------------------- 0 0 1-1-1 Down ITU 0 ITU92 1 0 3-3-3 Down ITU 2 ITU92 2 0 2-2-2 Up ITU 1 ITU92 3 0 3-3-3 IP ITU ITU92 4 0 1-1-1 IP ITU ITU92-------------------------------------------------------------------------------

STPOPC 1-1-1DPC 3-3-3

OPC 1-1-1 DPC 3-3-3

OPC 1-1-1 DPC 3-3-3

MTP3

Scope SGW1

Cmblinkset 0

Cmblinkset 2

M3UA Route Filter Parameter (for M3UA packets sent to AS)---------------------------------------------------------AS OPC OPC-Mask DPC DPC-Mask SLS SLS-Mask SIO SIO-Mask 1 1-1-1 14 2-2-2 0 0 4 0 4

MTP3 Loopback routing : confused

M3UA

In the same network, the same DPC is configured for both TDM and IP direction, confused.


M3UA Terminology

• Routing Key - A set of SS7 parameters and parameter values that uniquely define the range of signalling traffic to be handled by an AS.

A routing key is essentially a set of SS7 used to filter SS7 messages.

Normally a routing key may be consist of :

1) DPC

2) SIO + DPC

3) SIO + DPC +OPC

4) SIO + DPC + OPC + SLS (CIC)

7510:

1) Routing key is named as route filter.

2) SIO is pationed into two parts: SSF + SI.

3) SSF is defined as m3ua network paramter.

4) SI is defined as route filter parameter.


M3UA Terminology

• Routing Context - A value that uniquely identifies a Routing Key.

7510 use AS id as routing context.

• Application Server (AS) - A logical entity serving a specific Routing Key.

AS and Routing Key has a 1:1 relationship.

7510 is an SGP, it don’t provide any mtp3 user service, on 7510, AS is the image of MGC service entity.

• Signalling Process- A process instance that uses M3UA to communicate.

with other signalling processes.

on 7510, ASP is the image of remote ASP.

ASP and SCTP association has a 1:1 relationship.


ASP3

ASP2

ASP4

ASP1AS1

AS2

AS3

AS4

Germany

SEP2

SEP3

1-2-2

France

2-2-2

network2

network2

PSTN transfer IP

SGW

MGC2

MGC1

LS1


M3UA Terminology

• Network Appearance – an integer shared by SG and AS. Used to identifies the specific SS7 network that an SS7 node belongs to.

7510 use network id as network appearance.

• Signalling Point Management Cluster (SPMC) - The complete set of AS under a single MTP entity in a specific Network Appearance. SG may also be a member of SPMC.

• IP Server Process (IPSP) - A process instance of an IP-based application. Essentially same as an ASP, except that it uses M3UA in a point-to-point fashion


M3UA Application Model : SGP-ASP (7510 )

MTP2

MTP3

IP

SCTP

ASP

MTP2

NIF

SCTP

IP

Signalling Gateway

IP

SEP

L1 L1

MTP3

ISUP

M3UAM3UA

ISUP

SG don’t provide any MTP3 User Service.

SS7


M3UA Application Model : IPSP-IPSP

IP

SCTP

IPSP2

SCTP

IP

IPSP1

M3UAM3UA

No MTP function is required. No SGP function is rquired.

SCCPSCCP

SCCP UserSCCP User


M3UA Application Model: SGP Resident SCCP Layer

MTP2

MTP3

IP

SCTP

MGC

MTP2 SCTP

IP

Signalling Gateway

ethernet

SEP/STP

L1 L1

MTP3

SCCP

M3UAM3UA

SCCP

SG perform the SCCP Global Title Translation (GTT) function.

E1/T1

SCCP USER SCCP


M3UA Architecture Model: mated SGs.

SG 1 and SG 2 have the same Routing Key (they serve the same AS).

+ ++ +

+ +

+

+

+

+

+

+ +

+

+

+ +

+

+

+

+

+

+

SEPORSTP

SS7 links

SG 1“STP”

*

SG 2“STP

”

IP networkASPs

Mtp2/M2PA


M3UA Architecture Model

An SG is patitioned into multiple networks.

+

+

+++

+

+

+++

+

++

+

+

+

+

SEP

SEP

SS7 links

SG

SS7 Ntwk“A”

SS7 Ntwk“B”

M3UA

ASPs


M3UA Common Message Header

The common message header is same for IUA/M2UA/M3UA/V5UA.


M3UA Message Class

0 Management (MGMT) Message

1 Transfer Messages

2 SS7 Signalling Network Management (SSNM) Messages

3 ASP State Maintenance (ASPSM) Messages

4 ASP Traffic Maintenance (ASPTM) Messages

5 Reserved for Other Sigtran Adaptation Layers




9 Routing Key Management (RKM) Messages

10-127 Reserved by the IETF

128-255 Reserved for IETF-Defined Message Class extensions


M3UA and MTP3 mapping (Transfer message type)

0 Reserved 1 Payload Data (DATA) 2 to 127 Reserved by the IETF 128 to 255 Reserved for IETF-

Defined Transfer extensions

First bittransmitted

SISSFOPC DPCSLSslc

MTP3 message format


M3UA Data Fields : SI – Service Indicator

Serviceindicator

DCBA DCBA

Sub-servicefield

4 4


SI value(4bits)

0x0

0x1

0x20x3

0x4

0x5

0x6

0x7

0xb~0xf

ServiceSignaling network managementmessages

Signaling network testing and maintenance messages

spare

SCCP

TUP

ISUP

Data User Part (call and circuit-related messages

Data User Part (facility registration and cancellation messages

Reserved for MTP Testing User PartBroadband ISUPSatellite ISUPspare

0x80x90xa


Serviceindicator

DCBA DCBA

Sub-servicefield


M3UA Data Fields : NI and MP

NI – Network Indicator

MP – Message Priority

The network indicator codes are allocated as follows: bits D C 0 0 International network 0 1 Spare (for international use only) 1 0 National network 1 1 Reserved for national use

4 4


M3UA Data Fields : SLS, OPC , DPC,

Figure 14/Q.704 Standard label structure

SLC OPC

ITU 48

1424

1424


ANSI

DPC SIO


M3UA SSNM Message Types

0 Reserved

1 Destination Unavailable (DUNA)

2 Destination Available (DAVA)

3 Destination State Audit (DAUD)

4 Signaling Congestion (SCON)

5 Destination User Part Unavailable (DUPU)

6 Destination Restricted (DRST)

7 to 127 Reserved by the IETF

128 to 255 Reserved for IETF-Defined SSNM extensions

Note: except DAUD & SCON, other message types are sent from SG to ASP.


M3UA and MTP3 interactive : UPU

• If AS is not active or pending, when message with DPC 2-2-2 reach SGW from mtp link, SGW will reply with UPU

SP A(PC: 1-1-1)

ASP1(PC: 2-2-2)

SP B(PC: 3-3-3)

SS7 link

Germany

France A7510

SCTP association

User Data


OPC 1-1-1 DPC 2-2-2

MTP3

UPU (AS1 not

active)

Cmblinkset 2


ASP4(PC: 4-4-4)

ASP2(PC: 2-2-2)

ASP1

ASP2

AS1

ASP4AS2

M3UA


M3UA and MTP3 interactive : DUPU

• If a UPU is received from tdm link, SGW will send DUPU to All Active ASPs in the same network.

SP A(PC: 1-1-1)

ASP1(PC: 2-2-2)

SP B(PC: 3-3-3)

SS7 link

Germany

France A7510

SCTP association

User Data


APC 1-1-1

MTP3

Cmblinkset 2

ASP4(PC: 4-4-4)

ASP2(PC: 2-2-2)

ASP1

ASP2AS1

ASP4AS2

M3UA

DUPU

UPU

APC 1-1-1

DUPU APC 1-1-1

DUPU APC 1-1-1


M3UA SSNM DUPU message format

User value:0 to 2 Reserved 3 SCCP 4 TUP 5 ISUP6 to 8 Reserved 9 Broadband ISUP 10 Satellite ISUP 11 Reserved 12 AAL type 2

Signalling 13 Bearer

Independent Call Control (BICC)

14 Gateway Control Protocol

15 Reserved


M3UA and MTP3 interactive : DUNA/DAVA/DRST

• For a MTP3 route to ‘down’ direction, if it becomes unreachable, a DUNA will be sent to All ASPs in the same network (in case ASP is active). If it becomes reachable, then a DAVA will be sent to All ASPs.

STP A(PC: 1-1-1) ASP1(PC: 2-2-2)

STP B(PC: 3-3-3)

SS7 link

Germany

France A7510

SCTP association

User Data

MTP3

Cmblinkset 2

ASP4(PC: 4-4-4)

ASP2(PC: 2-2-2)

ASP1

ASP2

AS1

ASP4AS2

M3UA

DUNA

TFP--->DUNA

APC 1-1-1

DUNA

APC 1-1-1

MTP3 Route table:Number of routes : 4-------------------------------------------------------------------------------Route-ID Network-ID DPC Direction(*) Protocol Cmblinkset-ID Restart------------------------------------------------------------------------------- 0 0 1-1-1 Down ITU 0 ITU92 1 0 3-3-3 Down ITU 2 ITU92 2 0 2-2-2 Up ITU 1 ITU92 3 0 4-4-4 IP ITU 3 ITU92 -------------------------------------------------------------------------------

APC 1-1-1

TFA--->DAVA

TFR--->DRST

DUNA


M3UA and MTP3 interactive : DUNA/DAVA/DRST

• For a MTP3 route to ‘down’ direction, if it becomes unreachable, a DUNA will be sent to All ASPs in the same network (in case ASP is active). If it becomes reachable, then a DAVA will be sent to All ASPs.

STP A(PC: 1-1-1) ASP1(PC: 2-2-2)

STP B(PC: 3-3-3)

SS7 link

Germany

France A7510

SCTP association

User Data

APC7-7-7

MTP3

Cmblinkset 2

ASP4(PC: 4-4-4)

ASP2(PC: 2-2-2)

ASP1

ASP2

AS1

ASP4AS2

M3UA

DUNA

TFP--->DUNA

APC 7-7-7

DUNA

APC 7-7-7

MTP3 Route table:Number of routes : 5-------------------------------------------------------------------------------Route-ID Network-ID DPC Direction(*) Protocol Cmblinkset-ID Restart------------------------------------------------------------------------------- 0 0 1-1-1 Down ITU 0 ITU92 1 0 3-3-3 Down ITU 2 ITU92 2 0 2-2-2 Up ITU 1 ITU92 3 0 4-4-4 IP ITU 3 ITU92 4 0 7-7-7 Down ITU 4 ITU92-------------------------------------------------------------------------------

SP 7-7-7

APC 7-7-7

TFP

TFA--->DAVA

TFR--->DRST

DUNA


M3UA SSNM DUNA/DAVA/DAUD/DRST message format


M3UA SSNM Affected Point Code format

Mask: identifies how many bits of a Point Code are wildcarded.


M3UA and MTP3 interactive : SCON –Remote Congestion

When TFC is received , MTP3 record the congestion level, and generate a SCON to M3UA. Later, if MTP3 receive a message from M3UA, and message priority < TFC congestion level, then SCON will be generated to M3UA.

Sp A(PC: 1-1-1) ASP1(PC: 2-2-2)

SP B(PC: 3-3-3)

SS7 link

Germany

France A7510

SCTP association

User Data

APC 1-1-1, L=2

MTP3

Cmblinkset 2

ASP4(PC: 4-4-4)

ASP2(PC: 2-2-2)

ASP1

ASP2

AS1

ASP4AS2

M3UA

SCON

APC 1-1-1, L=2

SCON

APC 1-1-1, L=2


APC 1-1-1, L=2

TFCSCON

Congestion level=2


M3UA and MTP3 interactive : SCON –Remote congestion

When TFC is received , MTP3 record the congestion level, and generate a SCON to M3UA. Later, if MTP3 receive a message from M3UA, and message priority < TFC congestion level, then SCON will be generated to M3UA.

Sp A(PC: 1-1-1) ASP1(PC: 2-2-2)

SP B(PC: 3-3-3)

SS7 link

Germany

France A7510

SCTP association

User Data

MTP3

Cmblinkset 2

ASP4(PC: 4-4-4)

ASP2(PC: 2-2-2)

ASP1

ASP2

AS1

ASP4

AS2

M3UA

DPC 1-1-1, MP=1


SCON

DPC 1-1-1, MP=1

APC 1-1-1, L=2


M3UA and MTP3 interactive : SCON---local congestion

For a mtp3 international route (defined by m3ua network SSF), if the route is of local congestion (any link of this route enter congestion , then route congestion), a message from M3UA using this route will generate a SCON

For a mtp3 national route, if MTP3 receive a message from M3UA, and message priority < the selected link’s congestion , then SCON will be generated to M3UA

Sp A(PC: 1-1-1) ASP1(PC: 2-2-2)

SP B(PC: 3-3-3)

SS7 link

Germany

France A7510

SCTP association

User Data

Cmblinkset 2

ASP4(PC: 4-4-4)

ASP2(PC: 2-2-2)

ASP1

ASP2

AS1

ASP4

AS2

M3UA

DPC 1-1-1, MP=1


SCON

DPC 1-1-1, MP=1

APC 1-1-1, L=2

MTP3p1

p2

p3

p1, p2, p3: congestion threshold; Discard priority=0


M3UA and MTP3 interactive : M3UA trigger TFC

Sp A(PC: 1-1-1)

ASP1(PC: 2-2-2)

SP B(PC: 3-3-3)

SS7 link

Germany

France A7510

SCTP association

User Data

Cmblinkset 2

ASP2(PC: 2-2-2)

ASP1

AS1

M3UA

DPC 2-2-2

MTP3 Route table:Number of routes : 3-------------------------------------------------------------------------------Route-ID Network-ID DPC Direction(*) Protocol Cmblinkset-ID Restart------------------------------------------------------------------------------- 0 0 1-1-1 Down ITU 0 ITU92 1 0 3-3-3 Down ITU 2 ITU92 2 0 2-2-2 Up ITU 1 ITU92-------------------------------------------------------------------------------

MTP3

p1, p2, p3: congestion threshold;

ASP2

p1

p2

p3

DPC 2-2-2

TFC


M3UA and MTP3 interactive : M3UA trigger TFC

STP A(PC: 1-1-1)

ASP1(PC: 2-2-2)

SP B(PC: 3-3-3)

SS7 link

Germany

France

A7510

SCTP association

User Data

Cmblinkset 2

ASP2(PC: 2-2-2)

ASP1

AS1

M3UA

MTP3 ASP2

TFC

OPC 7-7-7 DPC 2-2-2

OPC 7-7-7 DPC 2-2-2

SP B(PC: 7-7-7)

SP

MTP3 Route table:Number of routes : 4-------------------------------------------------------------------------------Route-ID Network-ID DPC Direction(*) Protocol Cmblinkset-ID Restart------------------------------------------------------------------------------- 0 0 1-1-1 Down ITU 0 ITU92 1 0 3-3-3 Down ITU 2 ITU92 2 0 2-2-2 Up ITU 1 ITU92 3 0 7-7-7 Down ITU 3 ITU92-------------------------------------------------------------------------------

OPC

7-7

-7D

PC 2

-2-2

OPC 2-2-2 DPC 7-7-7

APC 2-2-2 CPC 7-7-7

SCON

CPC: concerned point code


M3UA SSNM SCON Message Format

Concerned Destination:

only used if SCON is sent from ASP to SG. It contains the point code of the originator of the message that triggered the SCON message. TFC is sent from SG to the Concerned DPC

using the single Affected DPC contained in the SCON message to populate the (affected) Destination field of the TFC message


M3UA AS state machine

AS active: means that Application

server is ready to process the

specific traffic. Only at AS-

ACTIVE state, User Messages (TUP, ISUP, …)

can be transferred to m3ua peer.

7510: don’t support

Broadcast traffic mode.

AS-INACTIV

E

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

AS-DOWN

One ASPTranstoASP-INACTIVE

All ASPTrans to

ASP-DOWN

Tr Expiry and no ASPIn ASP-INACTIVE state)

Last ACTIVEASP trans toASP-INACTIVEOr ASP-DOWN(state Tr)

Tr ExpiryAt least oneASP in ASP-INACTIVE

One ASPTrans to

ASP-ACTIVE

AS-PENDING(queuing)

One ASP Trans to ASP-ACTIVEAS-

ACTIVE


M3UA ASP state machine

Only at Active state, user data can be transferred to/from this ASP.

7510: an ASP can serve only one AS (routing context)

+

+

+ +

+

+

+

+

+

+

+

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+

+

ASP DOWN/SCTP CDI/SCTP RI

OtherASP in ASOverrides

ASP-ACTIVE+

+

ASPActive

ASPInactive

ASP-INACTIVE

ASP-DOWN

ASP DOWN/SCTP CDI/SCTP RI

ASPUp


M3UA ASPSM : ASP_UP

ASP Identifier: a unique value that is locally significant among the ASPs that support an AS. This value must be saved and used by Notify message.

7510: it is only meaningful to MGC, this value has nothing to do with UI ‘ASP id’.

asp_up_act.cap


M3UA ASPSM : ASP_UPACK

ASP Identifier: independent of the value in ASP_UP.


M3UA ASPSM : DOWN/DOWN-ACK

The INFO String in an ASP Down Ack message is independent from the INFO String in the ASP Down message (i.e., it does not have to echo back the INFO String received).

Asp_dn.cap

hbeat_data.cap


M3UA ASPTM : ASP_ACTIVE/ACTIVE_ACK

Traffic mode: 7510 don’t support Broadcast mode.Routing Context: only one Routing context is allowed (one

ASP can serve only one AS).The INFO String : independent from value in the ASP Active

message.

asp_up_act.cap

7510 Error and Cause:

1) Invalid routing context

Cause: 7510 use AS id as routing context. the Routing context value in ASPTM message is different from AS id cause this error.

2) No Configured AS for ASP

cause: m3ua route filter has not been configured for AS, or config failure.


M3UA ASPTM : Override Traffic Mode

Override: only one ASP is active at any moment.After send the Alt_ASP_ACT notify to ASP1, then ASP1 should

enter Inactive state.

SGP ASP2ASP1

ASP UPASP UP ACK

NOTIFY(AS-INACTIVE)

ASP ActiveASP Active Ack

ASP ActiveASP Active Ack

ASP UP

NOTIFY (Alt_ASP_ACT)

ASP UP ACK

NOTIFY(AS-INACTIVE)

NOTIFY(AS-INACTIVE)NOTIFY(AS-INACTIVE)


M3UA ASPTM : INACTIVE/INACTIVE_ACK

Routing Context: only one Routing context is allowed (one ASP can serve only one AS).

The INFO String : independent from value in the ASP Inactive message.

asp_ac_ina.cap


M3UA ASPTM : Notify

ASP Identifier: value contained in ASP_UP message.

Status Type =11 Reserved 2 (AS-INACTIVE)

3 (AS-ACTIVE) 4 (AS-PENDING)

Status Type = 21 Insufficient ASP

Resources Active in AS

2 Alternate ASP Active

3 ASP Failure


Agenda



7510_11:ACT-SCM:1.10(r0)>=3:diag:main:Vmgx:SGW2# vi sgw statusSGW-MNG: Status for all SGW entity:Sgw_id LBI admin_state ASP_id Service ASP_state SCTP_state 0 sfm enable 0 M2UA DOWN UP 10 IUA DOWN DOWN 1 pim2 enable 2 pim1 enable 0 M3UA DOWN UP

7510 M3UA SGW

after create an SGW on a pim card, you must enable

this SGW , otherwise M3UA will not work

SCTP association has been

established.

M3UA ASP is not Active, no User Message can be

carried.


7510 M3UA Stack Configurable Parameters

Congestion Queue Size............. …32767Congestion Level1 Size................ 32767Congestion Level2 Size............... 32767Congestion Level3 Size..........……. 32767As Recovery Timer.....................30000(ms)DUNA Settle Timer................... 1000(ms)Sequence Control Timer............. 1000(ms)

Congestion Queue Size : The number of messages in the congestion queue maintained for each association. When the queue reaches this size, further messages are dropped. Congestion Level1 Size: When the number of messages in the congestion queue reaches this level, SS7 congestion level 1 is declaredCongestion Level2 Size : When the number of messages in the congestion queue reaches this level, SS7 congestion level 2 is declared. Congestion Level3 Size : When the number of messages in the congestion queue reaches this level, SS7 congestion level 3 is declared. As Recovery Timer : refer to m3ua AS state machine. The time that AS stay at AS_PENDING state.DUNA Settle Timer : Period for which the SG will suppress the response DUNAs regarding an SS7 destination to give the ASPs the time to react to the previously sent DUNA message from the SGP.Sequence Control Timer : when mulitiply ASPs within an AS are active , if one ASP becomes unavailable, the traffic is diverted to other ASPs after sequence control time to avoid misequencing.


7510 M3UA SCTP Parameters

Signalling Gateway Role.......................... serverAutonomous SCTP Association...................... noOwn IP Address Number............................ 1Own IP Address................................... 10.11.12.111Own Port Id...................................... 2905

Signalling Gateway Role : if configured as client, and Autonomous SCTP Association is yes, 7510 will send init message to MGC. This function only works after system boot up. Autonomous SCTP Association : combined with Gateway Role.Own IP Address Number : how many own ip addresses have been configured. Automatically calculated. At most 10 own ip address can be configured.Own IP Address : IP addresses used for SCTP association. please make sure that own ip addresses are consistent with the value of ‘view ip if’. Own Port Id : SCTP association port .


7510 M3UA Network Parameters

M3UA Network Parameters-----------------------Network ID NA Sub Service Field PC Length SLS Length PC Format0 itu88 nat pc24 litsls4 8-8-8 24 ansi nat pc24 litsls5 8-8-8

Network ID : used as Network Appearance value in m3ua messages. Refered by mtp3 configuration.NA : SS7 variants. Supporting values are itu88|itu92|ansi|ansi96|china.

Sub Service Field : refer to the NI bits of SSF field. Refer to page M3UA Data Fields : NI and MPPC Length : Signalling Point Code Length. Supporting values are pc24|pc14 (diag UI) SLS Length : Signalling link selection bits number. For PC14, it is always 4. For PC24, it can be 4, 5, or 8.PC Format : Signalling Point Code layout. The following two basic PC format layouts are supported: - "x1-x2-x3", whereas x1+x2+x3 = 14 (ITU) or 24 (ANSI). - "x1-x2-x3-x4", whereas x1+x2+x3+x4 = 14 (ITU) or 24 (ANSI)


7510 M3UA AS Parameters

M3UA Application Server Table------------------------------ ID NwkId Ena/Dis Traffic Mode ASP Table 0 24 enabled override 0 1 0 disabled override 1

AS ID : used as routing context in m3ua messages. Refered by mtp3 linkset.NwkId : Network ID. This parameter specifiy the network properties of an AS.Ena/Dis : Administrator state. You must enable an AS , otherwise All the ASP controled by this AS will not work. Be careful, to make an AS to work, you must configure ASP(s) and route filter for this AS.Traffic mode : Override or loadsharing. For loadsharing mode, there are two traffic distribution policy among ASPs : rndrobin|sls . ASP Table : Automatically calculated. Same as AS ID.


7510 M3UA ASP Parameters

M3UA Application Server Process Table 1---------------------------------------Id Ena/Dis NA-Flag RKM-Flag Streams Port Remote Addresses Primary Path

4 enabled disabled disabled 128 2905 10.11.12.8 (enabled) - 5 enabled disabled disabled 64 2906 10.11.12.66 (disabled) 10.11.12.19 10.11.12.19 (enabled)

ASP Id : This parameter is only meaningful inside 7510. Has nothing to do with ASP Identifier parameter in m3ua messages.Ena/Dis : Administrator state. Be careful, to make an ASP to work, an ASP need to have at least an enabled ip address.NA-Flag : if set to enabled, the optional network appearance parameter will be included in m3ua messages when communicate with MGC . RKM-Flag : whether or not supporting RKM message. Streams: how many streams the sctp association will use. This parameters will be used during sctp establishment procedure. In most cases, stream number is set to mtp2 link number + 1.Port : the sctp port that MGC will use to establish association with 7510. It is a remote port.Remote Addresses: the ip addresses that MGC will use to establish association with 7510. max 4 remote address can be configured each ASP.Primary path: in normal case, traffic will be transported to MGC with primary ip address. But the fact is that this parameter has no effect.


7510 M3UA Route filter Parameters

M3UA Route Filter Parameter (for M3UA packets sent to AS)---------------------------------------------------------AS OPC OPC-Mask DPC DPC-Mask SLS SLS-Mask SIO SIO-Mask 0 51-2-1(0x330201) 24 36-2-1(0x240201) 0 0 5 0 4

the route filter is related to M3UA messages being sent to m3ua peer (ASP).AS : the id of the AS that serving this route filter(routing key) . AS and route filter has a 1:1 relationship. AS id is used as routing context value.OPC : Originating Point code of MTP3 user messages.OPC-Mask: how many bits of OPC are wildcarded. DPC : Destination Point code of MTP3 user messages. In most case, it is set to DPC of MGC.DPC-Mask: how many bits of DPC are wildcarded. In most case, it is set to 0.SLS: signalling link selection of MTP3 user messages.SLS-Mask: how many bits of SLS are wildcarded.SIO: Service Indicator (i.e, ISUP, TUP, …) of mtp3 messages. Totally 4 bits.SIO-Mask: how many bits of Service Indicator are wildcarded.

Assuming that MTP3 deliver a message to M3UA, the routing procedure is below:filtered= true;for each filter in the network that message comes from if (msg.opc&filter.opc-mask==filter.opc&filter.opc-mask && msg.dpc&filter.dpc-mask==filter.opc&filter.opc-mask && msg.sls&filter.sls-mask==filter.sls&filter.sls-mask && msg.si&filter.sio-mask==filter.sio&filter.sio-mask)

filtered = false; break;End forIf (filtered) drop the messageElse send message to MGCEnd if


Thanks

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