SIP over MPLS - Service Implementation

Aug 17, 2015 · 1038 words · 5 minutes read doc networks service provider safaricom

Wilber O. Wanjira¹ and Juma O. Kevin²
Principal Engineer - Integration¹ and Senior Engineer - Core Planning (Voice)²

Introduction

In this document, we share the deployed network architecture to provide SIP over MPLS. This model adopts the SIP protocol as signaling to set up a call and MPLS as a core network forwarding mechanism. SIP over MPLS will provide an alternative to SIP over dedicated Internet Access (the current and more typical deployment approach).

The benefits of running SIP over MPLS

Cross Platform Deployment - Unlocks deploying SIP over LTE, WIMAX & BESPOKE Solutions
Security; MPLS avoids exposure to the public internet, making SIP over MPLS more secure than over other transport options.
Improved call quality with low latency.
Less jitter
Better capacity control
End-to-End Quality of Service; MPLS will transport SIP using labels that will define the destination (Session Border Controller (SBC)) and the class of service it should receive. (explicit null)
Avoiding usage of public IPs which are limited resources
Ease of implementation as complex router configurations (over public deployments) are not required.
DRVS: Disaster Recovery Voice Signaling - Have the larger customer connected to both SBCs for redundancy. .

Core Configuration & Layout

Deployed e2e SIP Service delivery over MPLS [Schematic]

Connectivity between the SBC and Enterprise Core [Schematic & Configurations]

Physical & Logical Layout

Ports	IP	Description
GigabitEthernet0/0/0/9	x	primary physical link to SBC
GigabitEthernet1/0/0/9	x	secondary physical link to SBC
Bundle-Ether555	10.66.56.224/30	primary logical link to SBC
Bundle-Ether556	10.66.56.228/30	secondary logical link to SBC
x	10.66.56.138/32	SBC Signaling
x	10.65.83.97/32	SBC Media

QOA SBC PE Interface IPs

#physical interfaces configuration
interface GigabitEthernet1/0/5
 description to EBT_ASR_PE01 G0/0/0/9
 undo shutdown
 ip address 10.66.56.225 255.255.255.252
 
interface GigabitEthernet2/0/5
 description to EBT_ASR_PE02 G0/0/0/9
 undo shutdown
 ip address 10.66.56.229 255.255.255.252

#logical interface and route configuration
interface signal-if 3/0/4
description EBT_Signal_Service_IP
ip address 10.66.56.138 255.255.255.255
quit

ip route-static 10.221.0.0 255.255.255.0 10.66.56.226 description EBT_ASR_Signal
ip route-static 10.221.0.0 255.255.255.0 10.66.56.230 description EBT_ASR_Signal

sbc wellknownport clientaddr  10.66.56.138 sip 5060

SIP Trunk Configurations

#QOAGTMSS
ADD OFC: ON="EBTTEST_SIP", OOFFICT=CMPX, DOL=SAME, BOFCNO=1099, OFCTYPE=COM, SIG=SIP, SVQE=NO;
ADD BILLCTRL: OFFICENAME="EBTTEST_SIP", OOFFICT=OTHERNET, TZDSTNAME="INVALID";
ADD OFCMGW: ON="EBTTEST_SIP", MGWNAME="QOA_QOAGTMGW";
ADD SRT: SRN="QOA_SRT_EBTTEST_SIP", ON="EBTTEST_SIP", BFSM=INVALID;
ADD RT: RN="QOA_RT_EBTTEST_SIP", SR1N=" QOA_SRT_EBTTEST_SIP";
ADD RTANA: RSN="QOA_RSN_EBTTEST_SIP", RSSN="ALL", RN="QOA_RT_EBTTEST_SIP", ISUP=SIP_M;

ADD SIPTG: TGN="QOA_QOASBC_EBTTEST_CDC_SIP", CSCN="QOA_SIPTRUNK", SRTN="QOA_SRT_EBTTEST_SIP", BTG=1099, SBT=UDP, LOCALIP="10.66.52.2", OSU="10.66.57.129:5060", ISST=YES, ENTYPE=MSC, SIPRED=NO, IFADJUSTDATACODEC=NO;

#Logical Interface Configurations
interface signal-if 3/0/56
description EBUTEST_Signal_service_IP
ip address 10.66.57.129 255.255.255.255
quit
#
sbc mapgroup intercom-ip 11110
 description From_EBTTEST_To_Safaricom_Mapgroup
 clientaddr  10.66.56.138
 serveraddr  10.66.57.129 
 softxaddr 5  10.66.52.2
 softxaddr 10  10.66.52.10
 media-clientaddr 5  10.65.83.97
 media-serveraddr 5  10.66.56.254
 match source 10.221.0.2
 enable
#
sbc mapgroup intercom-ip 11120
 description From_Safaricom_To_EBTTEST_Mapgroup
 match source 0 begin 10.66.52.2 end 10.66.52.2
 match source 1 begin 10.66.52.10 end 10.66.52.10
 clientaddr  10.66.57.129
 serveraddr  10.66.56.138
 softxaddr 10.221.0.2
 media-clientaddr 5  10.66.56.254
 media-serveraddr 5  10.65.83.97
 enable
#
sbc wellknownport clientaddr 10.66.57.129 sip 5060
sbc wellknownport softxaddr 10.221.0.2 sip 5060
#
sbc iptrunk-intercom 58
ip 10.221.0.2 port 5060
description EBUTEST_SIP 
bind-mapgroup 11110   
enable
quit
#

#PE SBC Interface Configuration
interface Bundle-Ether555
vrf SBC_MPLS
ipv4 address 10.66.56.226/30
!
interface Bundle-Ether556
vrf SBC_MPLS
 ipv4 address 10.66.56.230/30

VRF Name > SBC_MPLS RD > 37061:749 Route Target Filters > SIP_SBC_Allowed_Subnets_Import, SIP_SBC_Signaling_Peer

#PE - SBC Failover Trigger
ipsla
operation 100
  type icmp echo
   vrf SBC_MPLS
   destination address 10.66.56.225
   statistics hourly
    buckets 2
   !
   timeout 5000
   frequency 60
  !
!
schedule operation 100
  start-time now
  life forever
!
track 100
type rtr 100 reachability
delay up 2
delay down 2
!
router static
 vrf SBC_MPLS
  address-family ipv4 unicast
   10.65.83.97/32 10.66.56.225 description QOASBC_Media_Primary track 100
   10.65.83.97/32 10.66.56.229 5 description QOASBC_Media_Secondary
   10.66.56.138/32 10.66.56.225 description QOASBC_Signaling_Primary track 100
   10.66.56.138/32 10.66.56.229 5 description QOASBC_Signaling_Secondary

Customer VRF Configurations

Schematic

Customer MPLS Block	VRF Name	RD	Interface	Route-Target Import
172.30.1.0/30	CUST_A	37061:456	Vlan 1000	37061:750

Head End (PE) Configurations

#customer VRF configuration
vrf definition CUST_A
 rd 100:456
 route-target export 37061:456
 route-target import 37061:456
 route-target import 37061:750
 !
 address-family ipv4
 exit-address-family
!
!
interface vlan 1000
 vrf forwarding CUST_A
 ip address 172.30.1.1 255.255.255.252
!
router bgp 37061
 !
 address-family ipv4 vrf CUST_A
  redistribute connected
    redistribute eigrp 456
 exit-address-family
!         
router eigrp 110
!         
address-family ipv4 vrf CUST_A as 456
  redistribute connected
  redistribute bgp 37061 metric 10000 1 100 1 1500
  network 172.30.1.0 0.0.0.3
 exit-address-family
!
end

#SIPoMPLS VRF configuration
vrf definition SBC_MPLS
 route-target import 37061:456

Import CUST_A route target community

extcommunity-set rt SIP_RT
  37061:750
end-set

#Import SBC filter rt into the Customer vrf.

Customer Edge (CE) Configurations

Deployment Model #1 - Link terminates on a Router. Customer PBX has WAN Port

Customer MPLS Block	SIP over MPLS Block	Protocol	WAN	LAN
172.30.1.0/30	10.221.0.0/30	EIGRP 456	FastEth0/0	FastEth0/1

#Customer Router Configurations
interface FastEthernet0/0
 ip address 172.30.1.2 255.255.255.252
!
interface FastEthernet0/1
 ip address 10.221.0.2 255.255.255.252
!
router eigrp SIPoMPLS
 !
 address-family ipv4 unicast as 456
  !
  topology base
  exit-af-topology
  network 10.221.0.0 0.0.0.3
  network 172.30.1.0 0.0.0.3
!

PBX will terminate on interface F0/2; directly or through a LAN switch. PBX port will be configured on the block range: on this example, the pbx IP will be 10.100.0.2/30 with a default gateway of 10.100.0.1 The block should be able to ping the SBC private MPLS IPs (Signaling and Media)

Deployment Model #2 - NAT

MPLS Block	SIP over MPLS Block	Protocol	PBX IP	WAN	LAN
172.30.1.0/30	10.221.0.0/30	EIGRP 456	192.168.0.2	FastEth0/0	FastEth0/1

#Customer Router Configurations - one to one NAT
interface FastEthernet0/0
 ip address 172.30.1.2 255.255.255.252
 ip nat outside
!
interface FastEthernet0/1
 description SIP
 ip address 192.168.0.1 255.255.255.252
 ip nat inside
!
!
router eigrp SIPoMPLS
 address-family ipv4 unicast as 456
  topology base
  exit-af-topology
  network 10.221.0.0 0.0.0.3
  network 172.30.1.0 0.0.0.3
!
ip nat inside source static 192.168.0.2 10.221.0.2
!

Deployed when customer already has an established PBX/ Voice LAN.Gateway of PBX has to be set to the router for NAT to function.

#Customer Router Configurations - PAT
access-list 114 permit udp any any range 10000 12000
ip nat pool voip-rtp 192.168.0.2 192.168.0.2 netmask 255.255.255.252 type rotary
ip nat inside source static udp 192.168.0.2 5060 10.221.0.2 5060 extendable
ip nat inside destination list 114 pool voip-rtp

Signaling port 5060 | Media Port Range 10000 - 20000

Deployment Model #3 - Link terminates directly to PBX

MPLS Block	SIP over MPLS Block	Protocol	PBX IP	WAN Interface
10.100.0.0/30	x	Static Route	10.100.0.0	PBX WAN Interface

MPLS IP configured on the PBX | PBX Gateway configured at the PE

SIPoMPLS - Service Implementation (SIPoMPLS-SAFARICOM-01)

Updated: 2015