# Codecs on SIP phones

<table border="1" id="bkmrk-yealink-t31p-grandst" style="border-collapse: collapse; width: 100%;"><colgroup><col style="width: 10.8462%;"></col><col style="width: 19.1895%;"></col><col style="width: 21.4541%;"></col><col style="width: 25.2704%;"></col><col style="width: 23.2397%;"></col></colgroup><tbody><tr><td>  
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</td><td>**Yealink T31P**</td><td>**Grandstream GRP-2602P**</td><td>**Cisco SPA-303**</td><td>**Linphone**</td></tr><tr><td>Versions</td><td>FW 124.86.0.40  
HW 123.1.1.0.2.0.0</td><td><div class="ant-row ant-form-item bak-form-item " style="display: block;"><div class="ant-col ant-form-item-label"><label class="" for="_0.8891145004928236" title=""><span class="text" style="right: 0px;" title="">Boot </span><span class="ant-form-item-children">1.0.1.32  
</span><span class="text" style="right: 0px;" title="">Core </span><span class="ant-form-item-children">1.0.5.17  
</span><span class="text" style="right: 0px;" title="">Prog </span><span class="ant-form-item-children">1.0.5.5</span></label><label class="" for="_0.6789739635488562" title=""><span class="text" style="right: 0px;" title="">Locale </span><span class="ant-form-item-children">1.0.5.40  
</span><span class="text" style="right: 0px;" title="">Res </span><span class="ant-form-item-children">1.0.5.1</span></label></div></div></td><td>Software Versions:

 7.4.9c, 7.5.2

Hardware Version:

 1.0.1

</td><td>Android 9+:

 v6.2.3 (7 Jul 2026)

</td></tr><tr><td>in order of priority</td><td>**Opus**

**G722**

**PCMA**

**PCMU**

legacy:

**G729AB**

G729

**G726/40 kbps**

G726/32 kbps

G726/24 kbps

G726/16 kbps

**iLBC/15.2 kbps**

iLBC/13.3 kbps

**G723.1/63 kbps**

G723.1/53 kbps

</td><td>**Opus**

**G722**

**PCMA**

**PCMU**

legacy:

**G.729A/B**

**G.726-40 kbps**

**G.726-32 kbps**

G.726-24 kbps

G.726-16 kbps

**iLBC**

G.723.1 kbps

</td><td>not supported: Opus

**1) G722**

G711u

G711a

legacy:

**2) G729a**

**3) G726-40**

G726-32

G726-24

G726-16

not supported: iLBC

not supported: G.723

</td><td>**Opus/48 kHz**

**G722/8 kHz**

**PCMU/8 kHz**

**PCMA/8 kHz**

legacy:

**G729/8 kHz**

not supported: G.726

**iLBC/8 kHz**

not supported: G.723

other codecs enabled:

**L16/44.1 kHz**

**speex/32kHz**

**speex/16 kHz**

iSAC/16 kHz

BV16/8 kHz

GSM/8 kHz

(priority order can not be defined in the admin UI)

</td></tr><tr><td>Config variables</td><td>  
</td><td>  
</td><td>Use Pref Codec Only: no

G729a Enable: yes

G722 Enable: yes

G726-16 Enable: no

G726-24 Enable: no

G726-32 Enable: no

G726-40 Enable: yes

Release Unused Codec: no

Use Remote Pref Codec: yes

Codec Negotiation: list all

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