IETF 86th

Considerations with WebRTC in Mobile Networks

draft-reddy-rtcweb-mobile-02 IETF 86-Oralando, March 2013

T. Reddy, J. Kaippallimalil, Ram Mohan. R and R. Ejzak 1

IETF 86th

Agenda
Overview of in draft-reddy-rtcweb-mobile.
Discuss the issues mentioned in draft
Next Steps

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Introduction – Scope of this draft
This draft looks at following aspects of webRTC from mobile networks perspective: – webRTC QoS in cellular networks – Mobility in Cellular networks

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Application / Service Layer UL Traffic Flow Aggregates UL-TFT UL-TFT → RB-ID RB-ID ↔S1-TEID

UE

eNodeB eNB Radio Bearer

• • • •

DL Traffic Flow Aggregates

DL-TFT DL-TFT → S5/S8-TEID S1-TEID ↔S5/S8-TEID

Serving GW S1 Bearer

S5/S8 Bearer

PDN GW 3gpp 23.401 Figure 4.7.2.2-1

Traffic Flow Templates (TFTs) used to sort packets into bearers on the uplink (in the UE) and downlink (in the PGW) TFT specifies flows based on IP header fields (IP 5-tuple) and DSCP Each APN has a default bearer Dedicated bearers can be established on demand, typically initiated by the PCRF via an application interface (Rx).

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IETF 86th

Problems with Multiplexing 1. DSCP values might not be preserved across the remote peer's network, over the Internet, and into the local carrier's network. 2. OS limitations to set DSCP 3. TFT cannot currently distinguish between audio, video and data channels when multiplexed (if cannot use DSCP)

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IETF 86th

Possible Solutions 1. Disable Multiplexing 2. Extend Packet Filter to include RTP SSRC 3. Extend Packet Filter to include RTP Payload type •

RTCP packets should not receive priority lower than corresponding RTP streams –

•

Consider compound RTCP packets

Data channels receive default for 5-tuple –

Only the browser can offer relative priority among data channels due to encryption of SCTP 6

IETF 86th

Proxy Mobile IPv6 – traffic offload 802.11 AP

Access Network SIPTO

Media MAG

Home Routed Traffic

Internet

802.11 AP

UE roams from the local Access network

LMA Macro Cell Access

Home Network

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IETF 86th

SIPTO – Selected IP Traffic Offload • In 3GPP when traffic is offloaded at TOF • If UE roams out of the coverage of RNC then it cannot reach the remote peer. • Possible solutions to solve the problem Mobility using ICE (MICE)

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IETF 86th

Next Steps • Request for more reviews

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