cisco unified communications manager - sip...

Cisco Unified Communications Manager - SIP URI and ILS

Akhil Behl – Solutions Architect (Cisco AS)

Aashish Jolly – Network Consulting Engineer (Cisco AS)

© 2014 Cisco and/or its affiliates. All rights reserved.

Agenda

• An Introduction to SIP Uniform Resource Identifier (URI)

• An insight to Intra-Cluster URI Dialing

• An insight to Inter-Cluster Lookup Service (ILS) networking

• An Introduction to Blended Addressing

• Conclusion

• CCIE Collaboration Quick Reference

• QA

3

An Introduction to SIP URIs


What is SIP URI?

• A SIP Uniform Resource Identifier (URI) identifies communication resources

• A SIP URI can be related to an email address

• Gives the end user the ability to dial via username in a Cisco Unified Collaboration network

• The most general form is: sip:user:password@host:port;uri-parameters?headers

5

The fundamentals of a SIP URI

sip:user:password@host:port;uri-parameters?headers




Why do I need SIP URIs?

• SIP URIs have been around for sometime and are native dialing method in SIP based video equipment

• Offer extended support for SIP video endpoints registered with Communications Manager for example better integration with other call controls where URI dialing is the native dialing habit (e.g. VCS)

• Offers unambiguous dialing from directories

• Enables easier B2B video call routing

6

The need for using SIP URIs


Limitations/Caveats with SIP URIs

• SIP URIs can not be used for PSTN calls; as long as there’s no mapping to E.164 number

• Only a subset of phones support URI dialing

– 99XX, 896X phones (except transfer, conferencing, forwarding)

– Jabber Client

– Video Endpoints

7

The downsides of SIP URIs


Decoding a SIP URI

• Example of a SIP URI: sip:[email protected]:5060

• In a Cisco Collaboration setup following specifics apply to a SIP URI’s construct

– User(name) is optional however, CUCM does not support URIs without username

– uri-parameters and headers are optional

– Passwords are not recommended

– host: can be an FQDN or an IP address

8

Username FQDN SIP Port

Understanding the Structure of SIP URI

sip:[email protected]:5060

sip:[email protected]:5060


SIP URI vis-à-vis Regular CUCM DNs

• Dialed “numbers” can contain: +, 0-9, *, A-D

• SIP Profile offers “Dial String Interpretation”; relevant for calls from endpoints and trunks

• “user=phone” tag in request URI forces treatment as numeric URI

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Comparing SIP URI and DN


CUCM (Alphanumeric) SIP URI Concepts

10

• CUCM DN is aliased by alpha URI i.e. in CUCM all endpoints will still have a DN along with defined SIP URI

• IP Phones always register via the DN and; do not necessarily even know that there is an associated alpha URI

• Up to 5 SIP URIs can be associated with a DN. Only one is marked as primary. Primary URI is used as blending identity for that DN

CUCM SIP URI Fundamentals


Adding a SIP URI Manually or via End User Page

11

• To add a SIP URI for a DN manually, go to Device > Phone > Click the DN > Define SIP URI under Add Directory URIs

• To add a SIP URI from End User page

– Configure Directory URI on End User page

– Associate endpoint (define digest user on phone; also creates association)

– Set Primary Extension

– Primary URI is automatically set; can not be deleted

– Additional URIs can still be configured

Adding a SIP URI to Corresponding CUCM DN

An Insight to Intra Cluster SIP URI Dialing


SIP URI Dialing Rules

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• URIs can be called if the URIs’ partition is member of calling CSS

• CSSs can contain DN and URI partitions

• Partitions can contain DNs and URIs

• CSS/Partition logic for URIs is identical to DN logic

• URIs need to be unique in partition

• No wildcards; always full match based on username/domain

• Partition order used as tie-breaker if same URI exists in two partitions

Dialing to/from a SIP URI


SIP URI Call Routing

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• Calling a URI takes a different path compared to dialing a regular CUCM DN

• URI routing does not have the concept of translation patterns; no equivalence to block patterns

• Only option for calling party transformation is the outbound calls calling party transformation CSS on calling endpoint or calling endpoint’s device pool

Dialing an Alphanumeric SIP URI


SIP URI Class of Service (Cos)

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• Default “Directory URI” partition has ALL auto-generated user based URIs

• There’s practically no way to differentiate different user groups based on auto-generated user based URIs

• If different user groups are required you need to explicitly provision the URIs in user group specific partitions and create appropriate CSSs

Dealing with SIP URI CoS

Demo – CUCM SIP URI Dialing

An insight to Inter Cluster Lookup Service (ILS) networking


Inter Cluster Lookup Service (ILS)

18

• Host part of URIs might identify home cluster however, problems start if URI scheme is flat. CUCM requires hierarchical URI scheme to identify the target URI e.g. [email protected] instead of [email protected]

• Need mechanism that allows propagation of individual SIP URIs between call controls and helps binds SIP URI with an attribute that allows routing to URI’s home cluster

• ILS allows:

– Each call control to replicate it’s SIP URIs to it’s neighbors

– Each call control to announce “SIP route string” together with the SIP URIs such that routing of SIP URIs is not based on URIs’ host part, but on SIP route string

Understanding the need for ILS

mailto:[email protected]



How ILS networking helps in Inter Cluster Dialing? Insight to ILS networking

19

• Call controls (CUCMs) establish ILS Exchange post which, URI information is flooded and each call control creates table with URIs and associated SIP route strings e.g.

– [email protected] > ind.cisco.com

– [email protected] > us.cisco.com

• SIP route strings are then routed by SIP route patterns to the destination cluster




ILS based Call Routing

20

• ILS based call routing proceeds as follows:

– [email protected] dials [email protected]

– CUCM’s call routing logic determines that the dialed URI is not a local URI

– ILS lookup leads to routestring us.cisco.com

– Call gets routed using SIP route pattern us.cisco.com

– At remote cluster, [email protected] is routable using the incoming trunk’s CSS (is a local URI)

Understanding ILS Call Routing





CUCM ILS Configuration

21

• ILS configuration can be summarized as follows:

– For every cluster participating in ILS networking, a unique ClusterID must be defined

– Cisco Tomcat Certificates must be exchanged among ‘Xnodes’ (nodes participating in ILS networking)

– For a full mesh connected cluster, Hub cluster role should be selected under ILS configuration

– For other clusters (Spoke clusters) join Hub cluster and set Registration server as SME

– Configure and setup Intercluster Directory URIs and setup the clusters for ILS exchange

Overview of ILS Configuration

An Introduction to Blended Addressing


Blended Addressing – The Missing Piece

23

• An endpoint with SIP URI can be represented via two ways – DN or URI

– In CUCM URIs are assigned to DNs, DNs are the “primary” identity, Devices register using DNs

• What is the “correct” identity to be presented during calls – DN or URI? The answer is, it mainly depends on the devices involved in the call if they support URI dialing or not

• “Blended Identity” – combination of DN and URI.

– DN URI: look at primary URI configured on DN

– URI DN: search for DN that has the URI as primary URI

Understanding Blended Addressing Fundamentals


CUCM Blended Addressing Dialing

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• During a call when endpoints have blended addressing, Remote Party ID (RPID) carries both URI and DN

– [email protected] dials [email protected]

– Destination is SIP URI

– Blend DN for calling party +1919999000 > [email protected]

– Lookup [email protected]

– Blend called party [email protected] > +19193333000

– If calling a URI enabled endpoint, initiate INVITE with RPID <sip:[email protected] :+19199990000>

– If calling a non URI enabled endpoint, initiate INVITE with RPID <sip:+19199990000>

– Ringing with RPID sip:[email protected]:+19193333000

– Blended Alerting ID: +19193333000 > [email protected]

Blended Addressing Insights






sip:[email protected] :+19199990000



sip:+19199990000


Conclusion


SIP URI – There’s a lot to it!

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• SIP URIs enable CUCM administrators to offer user friendly dialing. Most helpful with Video and Voice equipment especially in B2B, people don’t have to remember numbers, can use usernames/email addresses to dial

• Inter Cluster dialing is simplified by ILS and enables clusters to build routing logic that is both scalable and manageable

• Blended identity allows dialing within and outside of endpoints/devices supporting SIP URI

The next level of Collaboration

CCIE Collaboration Quick Reference


CCIE Collaboration Quick Reference

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28

One stop reference guide for CCIE Collaboration exam

http://click.linksynergy.com/fs-bin/click?id=aV8WWcTd0Yc&offerid=145238.10000399&type=3&subid=0





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